HELP! 12v issues.

[03heritagerider]

When plugged into shore power all 12v systems are off. Checked fuses and breakers also checked campground main power source and breaker at shore power box.

With inverter on I get 110 power to Microwave, tv's etc. I have to start the engine to get power to start the generator.

When generator is started, 12v lights are dim. The invert indicator light is blinking slowly.

Anybody got any ideas?

[tarheel]

I just went through the same problem last week. I have 12 V wet cell batteries for my house 12 V use from my converter in my Tourmaster. My batteries were toast and had to be replaced. They tested the batteries after they were removed and one was totally dead and the other was barely putting out anything. I had charged them the night before and they lost their charge almost instantly.

[03heritagerider]

Sorry to hear that, but I'm not sure that helps me. My batteries are 90 days old. When gen is on, everything seems O.K. Fridge goes to ac. When gen is off and shore power is plugged in, the fridge is OFF...no gas...no ac not even the light comes on. I have to start the coach to get the gen to start.

Don't know if I'm dealing with a bad set of batteries, a bad inverter, wiring problem or a bad transfer switch.

Couple years back I had to change the transfer switch (under bed). Could that be the problem again? If so, can I bypass the switch and make a direct connection from shore power? Would that harm anything?

[03heritagerider]

O.K. I did some testing on the transfer switch. Here are the results:

With generator running-inverter off-shore power off-testing the lines from the generator...
power to both red and black - LED indicator GREEN

With generator running-inverter off-shore power off-testing the lines from the inverter...
power to both red and black-LED indicator GREEN

With generator running-inverter off-shore power off-testing the lines from shore power...
no power to red or black-LED indicator GREEN


With inverter on-generator off-shore power off-testing the lines from the inverter...
no power ro red or black-LED indicator OFF

With inverter on-generator off-shore power off-testing the lines from the generator...
no power to red or black-LED indicator OFF

With inverter on-generator off-shore power off-testing the lines from shore power...
no power to red or black-LED indicator OFF


With shore power on-inverter off-generator off-testing the lines from shore power...
Power to both red and black-LED indicator OFF

With shore power on-inverter off-generator off-testing the lines from the inverter...
Power to both red and black-LED indicator OFF

With shore power on-inverter off-generator off-testing the lines from the generator...
No power to red or black-LED indicator OFF

I would think that in any mode the LED indicator should be GREEN. Should I, or could I, disconnect the lines from the inverter? It seems that my house batteries are running low while shore power is on. Last night we came back to the coach after about 10 hours and we had no lights, no fridge, and I had to start the engine to get the generator to turn over. It had obviously gone out shortly before our retun, as the thermometer in the fridge was still reading 40 degrees.

Fridge will not switch to gas when power is off- no power to fridge (GAS OR AC) when inverter is on. Fridge on AC when generator or shore power is on.

Color me confused!

P.S. It's Sunday...can't get any help from dealers.

[03heritagerider]

Latest development...12v systems weak. When gen goes off all power to 12v items goes off. Pilot on water heater goes off and won't relight. Lights are dim. Fridge is off. A/C won't come on.

However, items plugged into 110 outlets work. Laptop is fully charged, phones are charging, TV and microwave are on, but A/C will and fridge will not run unless gen is running.

Got up this morning and no 12v lights. Pilot won't light. Fridge is off. Gen won't start unless I start engine first. BUT, power panel indicator light is green and shows house batteries are fully charged.

[RayChez1]

I had been out and had not read anything until today the 13th. Did you get your 12 volt system working or are you still down? I was wondering if you had been messing around with your inverter lately and might have crossed the two wires that look like tv wire plug ins to your inverter. The reason why you have lights when your generator is running is because you are getting direct current from the generator. You might also have a problem with the transfer switch on mine it is inside the inverter/charger.

[03heritagerider]

Ray, thanks. I have not resolved the issue yet. Don't think I mixed them up. but if I did, it was a while back when I posted that the lights on the control panel were blinking. (Mine look like telephone jack plugs - one is gray and the other is black) Someone said to un-plug them and re-plug them. But that was back in October and there was no issue all winter long in Florida. But, I did have to replace the house batteries on the way back in April.

If, by chance, I did reverse them, can I try to switch them now? If that was not the problem, will it create one?

Talked to an RV tech on Monday and he said to check push button breaker on inverter. It was popped out and would not go back. He obviously wants me to bring it in for service. I had to change the transfer switch once before (mine is under the bed) and I was going to start with that. Figured it's a cheap fix and if it's not the problem, I'll have a spare.

Had to start the generator this morning to get the jacks up and slides in to come home from NYC. Fortunately, we spent 12-14 hour days in Manhattan, so it was no big deal to not have a fridge. By the time we got back we crashed then got up and started again. We did have hot water (electric) and plugs for lamps. Closest to "camping" in a long time.

[RayChez1]

When my transfer switch was repaired on my Xantrex inverter in Portland, Oregon I went and pick it up on my toad and my coach was at SeaSide, Oregon in an RV park. So I hired an electrician to hook it up. I did not want any mistakes and end up messing up the inverter/charger. Anyways he crossed those two wires that plug into the inverter and my panel inside the coach was giving some weird readings with the lights, so I opened the window and yelled at the electrician that the inverter was not working right on the panel. I asked him if he might have plugged those two wires back wards. So he went and switched the wires and everything started working right. So I thought I would mention it just in case somebody could have plugged them backwards.
]
Not sure what kind of inverter/charger you have, but I have the 3K watt Xantrex 458 Freedom. You might want to call who ever manufactured your inverter and ask them what the problem might be and whether they think it is caused by the inverter. They usually will try and work with you.

[tarheel]

03heritagerider-
I hate to jump on your thread with another issue since you haven't solved yours as yet, but I read your comments about the lights on your inverter panel going off and on. You indicated you unplugged the wires going into your inverter and that took care of the problem. Was that correct, because I've been having the same issue with the lights going on and off?
Dick

[03heritagerider]

They weren't actually going on and off. They were more like going in a rotation pattern. My panel has three columns of lights "Share - Charge - Invert". Each column has about 10 lights in it. There are also the three battery status lights. The lights were actually blinking in a defined circular chase pattern. Someone told me to reset the system by unplugging the phone type cords going into the inverter and re-plug them. That stopped the blinking.

[RayChez1]

OK! The lights on the panel on mine will go in a circular movement only when somebody presses the buttons on the panel to Equalize the batteries. That will go on for eight hours then it will stop automaticly or you can also stop the Equalization manually. You do not want to Equalize without turning the power off to the rest of the coach. There are some boards that might get fried at such a high rate of charge.

[tarheel]

I called Xantrex today about my problem, or lack of one. I began noticing this winter while in Florida that my entire panel would go out and eventually come back on. Sometimes it would just be a minute and sometimes longer. The Xantrex tech told me it was designed to do that. When there is no load called for, batteries aren't charging, etc. the board goes to sleep, as he put it, until a function is called for.

Heritagerider- I hope you find out quickly what is going on with your system.

[RayChez1]

Tarheel
, I guess mine has never gone to sleep in nine years I have had the coach. My green orange or red are always on display on the panel. Every light is on as long as the shore power is hooked up or if the inverter is on, or the generator is running and charging. Never heard about the panel going to sleep. That is a new one on me.

[tarheel]

Ray-
I've had 5 MHs with an inverter and that is the first time I've noticed it happening. I have an inverter with a bank of 4 batteries, a converter with 2 batters in additon to my 2 chassis batteries. Most of the time when I noticed the lights going off was when I got up in the morning during my being stationary for 4 months in Floria. I'm sure there were times that there was no demand for any actions of the inverter. The tech I talked with was very sure of his answer, so I'm going with that. Hope he was correct!
Dick

[03heritagerider]

Mine are on all the time unless I turn everything off.

The circular blinking on mine went on for days, until I unplugged the "phone" lines. That was last October and until this weekend, everything functioned properly.

Got the coach in the driveway today and purposely did not plug it into the shore power. TV and microwave are off as expected. The control panel is completely out and I haven't turned on the inverter, but now everything else is working as you would expect.

These items would NOT work when connected to shore power this week, however today and not plugged into shore power:
I turned on the fridge and it immediately switched to gas and lit
All 12v lights now work
Water heater ignition clicked and it fired up

Tomorrow, I will plug it in to shore power and see what ceases to work.

[jtking]

I had similar problem with previous Coach (Fleetwood Discovery). After many hours of self diagnosis over 3-4 days I gave up and went to RV local service center. What the problem ended up being is the common (white) wire for the converter/inverter 110v circuit was loose where it connected to the ground bar inside and behind the 110v circuit breakers. It might be worth a try to check the tightness of all wires connected to the ground bar. Interestingly I had checked the voltage from each 110v circuit breaker to the ground bar itself (all tested good) but not to each actual common wire!

John

[RayChez1]

So what was the final outcome of your problem 03heritagerider? Don't leave us in suspense as to what the problem really was. The only time my Heart Interface Panel lights rotate in a circle is when it is equalizing the batteries. But in order to do that somebody had to have pressed two touch control buttons on that panel and the amp lights will go right away to around 16 amps of charging. :?

[nemo45]

Well what happened? Did you check the fuses on the converter? They are there if you hook up your batteries wrong. I accidently hit the positive pole with thje ground wire when installing new batteries and blew all three of the automotive type fuses on the converter. Didn't know it untill I saw low DC blinking on the refrigerator. Replaced the fuses and everything has been fine. On my motorhome(2006 Gulf Stream Tour Master)the xantex inverter really has nothing to do with the 12V as it doesn't have a built in converter in it. It might be nice if we knew what year and model you motor home is, we could be more specific with help.

[nomad]

Talked to an RV tech on Monday and he said to check push button breaker on inverter. It was popped out and would not go back. He obviously wants me to bring it in for service. I had to change the transfer switch once before (mine is under the bed) and I was going to start with that. Figured it's a cheap fix and if it's not the problem, I'll have a spare





Wiring wrong somewhere

[RayChez1]

Well what happened? Did you check the fuses on the converter? They are there if you hook up your batteries wrong. I accidently hit the positive pole with thje ground wire when the inv installing new batteries and blew all three of the automotive type fuses on the converter. Didn't know it untill I saw low DC blinking on the refrigerator. Replaced the fuses and everything has been fine. On my motorhome(2006 Gulf Stream Tour Master)the xantex inverter really has nothing to do with the 12V as it doesn't have a built in converter in it. It might be
nice if we knew what year and model you motor home is, we could be more specific with help.


What do you mean the investor/charger has nothing to do with 12volt? It inverts DC 12volts to Ac 110 volts and if you have the xantrex 458 it has a transfer board right in the investor.

[nemo45]

Well what happened? Did you check the fuses on the converter? They are there if you hook up your batteries wrong. I accidently hit the positive pole with thje ground wire when the inv installing new batteries and blew all three of the automotive type fuses on the converter. Didn't know it untill I saw low DC blinking on the refrigerator. Replaced the fuses and everything has been fine. On my motorhome(2006 Gulf Stream Tour Master)the xantex inverter really has nothing to do with the 12V as it doesn't have a built in converter in it. It might be
nice if we knew what year and model you motor home is, we could be more specific with help.


What do you mean the investor/charger has nothing to do with 12volt? It inverts DC 12volts to Ac 110 volts and if you have the xantrex 458 it has a transfer board right in the investor.

First what's an investor. I assume you mean an inverter. My inverter has nothing to do with the 12V system the runs the lights and everything else that is 12V in the coach. The converter and 2-12V house batteries take care of that. My inverter has no converter in it as some do, but it does invert 12dc supplied by the 4-6V batteries attached to it to 110V ac. This so you can operate things like a tv or a fan without running the generator. Also you can operate a residential type refrigerator while going down the road. Some inverters do have a converter in them and this does charge the house 12V batteries, but the inverter itself really has nothing to do with the house batteries.

[RayChez1]

You must have a completely different inverter then what I have. I have the Xantrex 458 Freedom 3000 Watt inverter/charger. The transfer switch is in the inverter/ charger. I know because I had a lose connection on the transfer switch and I took the inverter to the main Xantrex shop in Portland, Oregon. They found a lose connection to the board and got it fixed.

My inverter changes DC to AC from the four six volt batteries to operate the microwave/convection oven, televisions and any other AC product with the exception of the heat pumps/air conditioners. All the plug outlets are hot when the inverter/charger is on. Not like a lot of other entry level coaches where only a couple are hot when the inverter is on.

The charger on the inverter/charger, charges the house batteries only. It does not charge the chassis batteries. A person could find a way to charge both, but it was not the choice of the coach builder to do so.

Now as to the error I made in miss-spelling inverter and you making a big deal about it is kids stuff. We are grown men and most of us retired and don't give a hoot about a word that was not spelled correct.

[03heritagerider]

Hey guys!

Sorry to leave everyone in suspense, but it is still an ongoing issue.

I have the same inverter/charger as you Ray...Freedom 458.

We've been extremely busy the past month since we got back from the NYC trip when the lights went out.

I too was going on the assumption that the transfer switch was the culprit. When doing the testing, the LED indicator did not always light.

Ordering the IOTA ITS-50R Transfer Switch was no easy task. First, they don't make it anymore. The replacement is the PowerMax PMTS 50. I ordered the unit after talking to several distributors and was confident that it would be an easy swap. I replaced the IOTA about 5 years ago and it was a simple "take the old one out, and put the new one in".

When the new transfer switch arrived last week, it did not look right. After the holiday I called and went through a day of phone tag and e-mails to convince them it was not the unit I ordered. I finally had to send a photo to prove it. I'm now waiting for the replacement. Again, if that wasn't the issue, I'll have a spare.

The really strange thing now is that everything in the coach seems to be working correctly. I have it plugged into shore power (only 15 amp household current) and all seems O.K. When we got back from NYC, I purposely did not plug into shore power to see how long the batteries would last. It was almost two weeks and all the 12v items continued to work when I would go out and check.

The tech told me to check the push button breaker, but his description of it being tripped was a bit vague. When I touch the button, it seems loose, but does not seem to be "Popped Out!" I'm praying the problem is the transfer switch at $100.00 and not the inverter/charger at $1,000.00!

Don't know what the issue is yet...may need to do an exorcism :lol:

Thanks for your interest and I promise to keep you posted.

[nemo45]

You must have a completely different inverter then what I have. I have the Xantrex 458 Freedom 3000 Watt inverter/charger. The transfer switch is in the inverter/ charger. I know because I had a lose connection on the transfer switch and I took the inverter to the main Xantrex shop in Portland, Oregon. They found a lose connection to the board and got it fixed.

My inverter changes DC to AC from the four six volt batteries to operate the microwave/convection oven, televisions and any other AC product with the exception of the heat pumps/air conditioners. All the plug outlets are hot when the inverter/charger is on. Not like a lot of other entry level coaches where only a couple are hot when the inverter is on.

The charger on the inverter/charger, charges the house batteries only. It does not charge the chassis batteries. A person could find a way to charge both, but it was not the choice of the coach builder to do so.

Now as to the error I made in miss-spelling inverter and you making a big deal about it is kids stuff. We are grown men and most of us retired and don't give a hoot about a word that was not spelled correct.

Ok, I'll explain it again. My coach has eight batteries, two starting (chassis) batteries, two coach(house) batteries all 12V. It has a bank of four 6V batteries connected to the inverter. I too have a Xantrex Freedom 458 Series Inverter/Charger model no. 81-2010-12, but its 2000W. It does have a built in transfer switch but according to the Xantrex web site that is for the inverter only, to switch from the inverter to shore power when you plug in. I have a seperate transfer switch for the generator. This transfer switch for the generator is under the bed in the rear of the coach and clearly marked transfer switch, also under the bed is an Intellipower 9180 converter to which I have added a "charge wizard" to make it a three stage charger. The Intellipower converter maintains the two 12V coach batteries. I have also installed a Trick-L-Start 5 amp charger that charges the starting (chassis) batteries when you are plugged into shore power thru the converter. The inverter/charger chargers only the bank of 6V batteries and these supply 12V DC to the inverter to invert it to 110 AC. The inverter basically has nothing to do with the 12V system which supplies the lights, refrigerator control, vent fans, water pump, water heater ignition etc., that system is connected to the two 12V house (coach) batteries and the converter. Besides not running the A/C the inverter is not wired to the 110V to the water heater either. I don't how your coach is setup but above is the way mine is.
If I offended you with questioning "investor", I apollogize. It is kid stuff. But sometimes, I just can't help myself. Since this forum doesn't have spell check I read my post several times to make sure I have the words I know how to spell right before I post it. By the way, not all of us are men on this forum. Oops, there I go again.

[RayChez1]

OK, so you have eight batteries. Two twelve volt batteries for the chassis to crank the engine over. But this other is what throws a loop to me. You say you have two more twelve volt batteries for supplying power to the twelve volt lighting. Then you say you have four more six volt batteries, I imagine hooked up in series to supply power for??????? Are you saying these other four six volt batteries are used only when you use the inverter? If that is the case then you do have a weird set up.
On my Gulf Stream the six volt batteries hooked up in series which will give you twelve volts are used for the lights and also used when inverting to 110 volts.

I hardly use my inverter, but occasionally I will use it before we hook up to shore power in a camp ground to check if I have a spot where I can get satellite. That is the first thing I do when I arrive to a new preserve is check to see if the King dome can lock into the two satellites.

There is a box inside the bed box on mine that might also be another transfer switch, but I really have not looked at it that close.

[jtking]

My battery system is exactly like Don and Carols. The 4 six volt btys are dedicated specifically to the inverter and provide 110 v to all plugs in the coach when not connected to shore power or running on generator. There are two pairs wired in series and then the pairs are joined in parallel to provide 12v to the inverter. My TourMaster and I assume most have a residential refrigerator which only runs on 110v, therefore we ALWAYS need 110v power available. We can use the microwave, toaster, coffee pot,etc.,without being connected to shore power or running the generator. When shore power is unplugged or generator is shut down the inverter takes over instantaneously. The inverter will not run the roof A/C though.

The two 12v deep cycle (coach) btys run lights, water pump, ceiling vent fans, electric step, gas furnace, etc.

Hope this helps rather than confuse the issue.

John

[nemo45]

My battery system is exactly like Don and Carols. The 4 six volt btys are dedicated specifically to the inverter and provide 110 v to all plugs in the coach when not connected to shore power or running on generator. There are two pairs wired in series and then the pairs are joined in parallel to provide 12v to the inverter. My TourMaster and I assume most have a residential refrigerator which only runs on 110v, therefore we ALWAYS need 110v power available. We can use the microwave, toaster, coffee pot,etc.,without being connected to shore power or running the generator. When shore power is unplugged or generator is shut down the inverter takes over instantaneously. The inverter will not run the roof A/C though.

The two 12v deep cycle (coach) btys run lights, water pump, ceiling vent fans, electric step, gas furnace, etc.

Hope this helps rather than confuse the issue.

John

Exactly. Although, I do not have a residential Refrigerator. They went to residential refrig in 2007 mine is a 2006. We have a small 3 cu. ft. freezer underneath and will use the inverter when traveling for that. I don't understand why Ray doesn't get that you can have the inverter system and the coach 12V battery system seperated as ours are. I believe all the Tour Masters are like this.

[nemo45]

OK, so you have eight batteries. Two twelve volt batteries for the chassis to crank the engine over. But this other is what throws a loop to me. You say you have two more twelve volt batteries for supplying power to the twelve volt lighting. Then you say you have four more six volt batteries, I imagine hooked up in series to supply power for??????? Are you saying these other four six volt batteries are used only when you use the inverter? If that is the case then you do have a weird set up.
On my Gulf Stream the six volt batteries hooked up in series which will give you twelve volts are used for the lights and also used when inverting to 110 volts.

I hardly use my inverter, but occasionally I will use it before we hook up to shore power in a camp ground to check if I have a spot where I can get satellite. That is the first thing I do when I arrive to a new preserve is check to see if the King dome can lock into the two satellites.

There is a box inside the bed box on mine that might also be another transfer switch, but I really have not looked at it that close.

So, you have only six batteries total, four batteries for the inverter and two starting batteries? I don't understand why you think I have a wierd set up. It works fine. And, I like having the extra batteries and the systems seperate. I don't see it as being redundant, rather a feature that allows you to use both systems at the same time, while having less of a load on each.

[jtking]

With the side by side residential refrigerator we really didn't need the extra freezer so I took it out and use the storage space for other "necessities".

I think Ray has a system similar to what our Discovery had--two 12v chassis btys and two 6v coach btys in series to provide 12v to normal RV stuff and in addition provide 12v to 1000w (in our case) useless inverter connected to one plug!!

John

[RayChez1]

Nope! I have six batteries. Two chasis batteries 12 volt to start the cat engine. Then there are four deep cycle six volt batteries hooked up in series I believe to power any thing that is 12volt. Now if I am with out shore power THEN I turn on the 3000 watt inverter to run anything that requires 110 volts.

I can see if you have a residential type refrigerator where you need more batteries, but if you have the propane/electric 1200lrim, THEN you really do not need those two extra 12 volt batteries. Just extra expense because the four six volt would do the job. Maybe it is because you have a smaller inverter.

[03heritagerider]

I have what Ray has, except, I replaced the two 6v house batteries with 2 12v batteries. When boondocking (which is rare...just an overnight on the way to somewhere), then the inverter comes on to power 110 items like TV. Fridge goes on gas when not on shore power.

[03heritagerider]

O.K. I finally got the new Transfer Switch. The PowerMax PMTS 50 is slightly different from the IOTA (discontinued). I called the Power Max tech to verify the wire placement and put it in the coach.

Everything seems to be working fine, but I guess I won't be able to relax until I get to a park with 50amp service and see if the same issues arise as when we were in NYC in June.

If anything changes, I'll let you know. Thanks for all the input. :D

[03heritagerider]

O.K.
So it's been a little over a week since I installed the new transfer switch.

I went out to the coach today and guess what....no 12v power!

The Xantrex panel reads that the batteries are full (green)...the 110 system is working on shore power(TV, Microwave, wall plugs), but everything that runs off 12v is dead.

Nothing works when the inverter is on. No 12v or 110v
CORRECTION! with inverter on, 110v is on

Everything works with the generator on, but there is no power to start the generator unless I start the engine.

Am I missing something or do I need a new inverter???

[nemo45]

Did you check the 25amp breaker on the inverter itself.

[03heritagerider]

Did you check the 25amp breaker on the inverter itself.

That seems to be o.k. Talked to a tech from Xantrex and he had me check a few things and his conclusion was that the charger/inverter seems to be operating correctly (I'm not convinced). With shore power disconnected, the panel reads that the batteries are at 14v and fully charged. With the inverter on, the microwave and TV operate. But steps barely move, and house lights are dim. He suggested I get an electrician to see what may be drawing power.

However, that still doesn't make sense to me (and my very limited knowledge of the subject). If plugged into shore power, and the house batteries are charging, how can it draw more power than is being brought in.

If I liken it to water, how can a dripping faucet consume more water than can come in from the supply hose?

Also, with the generator running, 110v is fine but 12v power seems low and I must start engine to get generator to turn over.

Another curiosity...when I start the engine, I have full 12 power. The house lights, steps, etc. all come on. If I let it run a while, I seem to have stored some power. When the motor is off, I seem to be using power but not storing any.

Am I wrong assuming the house lights work off the house batteries?

It seems to me that I am running on two separate systems. Shore power gets me TV, microwave and plugs. The house lights, fridge and A/C will run until the batteries give out. (Fridge and A/C need 12v to operate their thermostats. Fridge won't even run on gas without 12v to operate the thermostat.) Then I must run the engine to charge the batteries.


UPDATE!

I called the Xantex tech line back again and told him about the 12v systems coming alive when the engine was running.

His conclusion was that it was "obvious that the 12v systems run off the chassis batteries and not the house batteries".

I don't think that's correct...if there isn't enough power to run the steps and some lights, there certainly wouldn't be enough power to start the engine! Am I right????

[RayChez1]

I believe you are right. I believe that you have a ground wire on your twelve volt system that is not getting a good ground and therefore you are not getting good continuity off your house batteries. Check all your ground wires coming off your house batteries.

Which Xantrex shop did you contact? "The one in Portland Oregon has a good reputation on fixing inverters and a very knowledgable young man was the tech when I visited last, about two years ago. Not sure if the same person still there, but if you have not called the Portland Xantrex shop, I would give them a call.

[03heritagerider]

I believe that you have a ground wire on your twelve volt system that is not getting a good ground and therefore you are not getting good continuity off your house batteries. Check all your ground wires coming off your house batteries.

I think you're getting closer to the issue Ray. I went to Advance Auto and bought a multi-meter (all I had were the idiot light testers).

I put the meter on one of the house batteries and it read 13.9v. Then I figured I would check the other one, but since it was jumped to the first one, I assumed it would read the same...But no!, it read 1.0v.

Back me up on this theory....
using two 12v deep cell batteries (positive to positive and negative to negative)
1. If they are connected properly, they should read the same.
2. If they do not read the same, then they are not (properly) connected (bad or loose ground)
then...
3. If they are not properly connected
a. one of the batteries can be bad or,
b. one battery is not being charged and thus discharging the other battery with use.

Have to go out now, but will check for responses later. Probably won't be able to check connections until the weekend.

Thanks everyone for your input.
Ray, Special thanks to you for your years of advice.

[RayChez1]

OK, now we are getting some interesting information when you mentioned one battery fully charged and the other almost completely dead. The two batteries should be hooked up parallel and you mentioned that they are. So if there are no loose connections on your parallel wiring, then what is causing your problem is that one battery that has shorted out and is bad. Needs to be replaced. But to make sure I would take that dead battery out and by itself hook up another battery charger and see what happens. If it charges right up, then it is a loose connection somewhere. If it does not and the charger shows a fault, then the battery is bad. Your two batteries hooked up parallel should give you 200 AH. What you are getting now is only half or 100 AH.

[03heritagerider]

Ray,

I'm going to try to get to the testing and charging today. I'll keep you posted.

Mike

[03heritagerider]

Eureka! I think!

One end of the jumper cable between the negative posts on the house batteries had come loose and was not making contact. The instant I pushed it on and tightened it, I could hear the charger start to hum.

I opened coach door and the steps swung out quickly and completely. I went inside and turned on all the lights and they were bright and shiny!

I'm trying to not get too excited, but the dramatic result of a few twists of a ratchet tell me the problem is resolved. Also, I'm a bit embarrassed that I didn't think of that first! :oops:

Many thanks to the great folks who shared their knowledge, experience and expertise. Oh yeah, and a hug from the wife! :D

[RayChez1]

I am glad you have solved the problem. Sometimes little things like that can be a pain.