Shore power requires engine running?!

[CptHaddock]

Hello everyone,

my '06 Sun Voyager (model 8379) won't run anything except electrical outlets from shore power unless the main engine is also running. If shore power is disconnected, lights, fans, AC etc. don't work with the engine running.

Unfortunately the generator is being obstinate (not starting) making it impossible to test that scenario.

I've tested all of the fuses, breakers and relays I can find to no avail. The two house batteries are brand new and I'm out if ideas on how to identify the source of the problem.

Any help or suggestions will be greatly appreciated!

James

[jeremyseattle]

Have you checked the interconnect switch? It goes between the house and chassis batteries. If on house mode, then everything DC should run off house batteries - and shore power will charge the house batteries. If on chassis mode, then the alternator powers house DC and charges the batteries.

My 93 Ultra stopped apparently charging the house batteries while on shore power a couple of days ago when I was messing with the fuse box, hooking up a new dashboard stereo. AC outlets were working, but I think I had knocked the wire loose (yellow wire that goes from the switch to under the dash) and the interconnect switch was stuck on chassis mode. I think the house batteries drained from not charging for a day or so, and the 12v fridge stopped working (low-voltage cutoff). Reconnected the yellow wire to 12v ignition voltage and everything started working again.

I don't know if this was the cause for sure - I'm actually about to post my own thread about the interconnect thing - but you might check!

[jeremyseattle]

my '06 Sun Voyager (model 8379) won't run anything except electrical outlets from shore power unless the main engine is also running. If shore power is disconnected, lights, fans, AC etc. don't work with the engine running.

Just re-read the above, and while I'm new, I think I have an understanding of what should work, when...

Battery-only: only 12v devices should work - lights, range hood, 12v fridge circuit (if equipped); water pump; water heater (control board); furnace fan; marker lights

Engine running: all 12v devices above along with cab climate control; in-dash stereo; turn signals (head/tail lights and hazards should always work)

Shore power: all 12v devices above along with power outlets; AC; microwave (via power outlet of course)

If 12v devices only work when the engine is running, then there's a problem with your house batteries - you say they're new, so the issue is with the interconnect like I mentioned before.

For 120v devices in the camper (coach), it should not matter if your engine is running or not; that just determines whether the batteries are being charged - that's just 12v stuff anyway.

On shore power, if your power outlets are working but your AC is not, then there's an issue with the AC or the 120v circuit powering it. You say you checked the breakers; you should pull the cover off the AC air intake and check for 120v there.

Like I said, I'm new to this, so I could be wrong...

[dan596]

Hello,
I was just wondering if you found a solution on this. I was thinking it was something wrong with your transfer switch. Transfer switch I speak is what switches your 120VAC circuits from running of shore power versus running off your generator. I was warned when I first got my rig to be very careful not run the generator when the shore power was plugged in or it will damage the transfer switch. I was thinking your switch could be damaged or mis-wired to only switch to the 'shore power' side when it is power somehow from the engine DC power.

[THenne1713]

LIGHTS ARE 12VDC and should work anytime, if Battery SWITCH is ON and Coach Battery GOOD?; Otherwise, you may have a tripped 12vdc CIRUIT BREAKER, next to the COACH BATTERY? BUT 12v Lights SHOULD also work off shorepower when plugged in, but sounds like 120vac NOT reaching CONVERTER, (which would also provide 12vdc) or maybe blown 30A FUSES if BATTERY INSTALLED BACKWARDS? (Fuses labeled REVERSE POLARITY). AIR CONDITIONER CONTROLS REQUIRE 12VDC, Too.