New Battery Going Flat and Alternator Not Charging

[Wakesupremo]

I posted recently about my battery going flat and the boost circuit not working. I have since tested and, the boost circuit does work but, my new replacement battery is still going flat. I have realised that I have never seen an ' exciter' light for the alternator. Does this mean that the alternator won't start charging without this?

 

[Chuck v]

First things first -- check that there are no parasitic drains on the battery when nothing is 'supposed' to be on... Even a 1 amp discharge over time will cause a battery to go flat.

If you do not have a real ammeter in the dash indicator array, use a clamp on meter to verify that charging is occurring when the engine runs. It is best to not rely solely on idiot lights...

 

[Wakesupremo]

Thanks again Chuck. Its now 'Dark oclock' here but I'll have a look in the morning. There is a voltmeter in the gauge cluster and, as you say, I can't rely on that but, that doesn't get above 12 volts. I know that alternators must have the 'exciter' to kick them into operation and, I'm fairly sure that I have never seen one light up. Hopefully I can sort it tomorrow as its the first outing towing the race car to the track tomorrow!! Might just be a bulb blown but, im never that lucky!

 

[Just two]

There was a recent post that Ford trucks have heavy power draws on there radios. Might be worth a check.

 

[HappyCamperBob]

I posted recently about my battery going flat and the boost circuit not working. I have since tested and, the boost circuit does work but, my new replacement battery is still going flat. I have realised that I have never seen an ' exciter' light for the alternator. Does this mean that the alternator won't start charging without this?

I had the same issue with my 2019 BT Cruiser 5255. It turned out that when the emergency brake is engaged, it energizes a relay which allows the slide-out to operate. As long as the emergency brake is engaged, the relay stays energized and thus slowly drains the battery. Additionally, the alarm system for the cab portion of the RV is a parasitic drain and will also deplete the cab battery over time. Until I can find the time to bypass the contact switch on the emergency brake and install a manual switch, I keep the emergency brake off except for extending and retracting the slide. Wheel chocks are a must. Also, I purchased two small solar panels from Amazon that keep the batteries topped off when I'm not using my RV. Hope this helps. Here's a screenshot of the solar panels on Amazon. Good luck!

 

[Wakesupremo]

Thank you for the replys. I had to swap the alternator the morning I left for the race track. I tested the old one and there was no 12 volt ign supply to it so I thought rather than try to diagnose that I just bought a 1 wire alternator and swapped it. That has worked I think!!!

 

[bmojmhs]

Check your fridge manual and see if yours has a fridge door heater. If the switch is on, it will draw power when everything is shut off and run down your battery.

 

[Just two]

There are some nice alternators replacements that are upgrades. I purchased one from Tucson Alternator it is rated at 400 amps.

Tucson Alternator Exchange & Copperstate Auto Electric