Batteries Are Good, But Lights Won't Come On

[jlacaeyse]

I have 1994 Winnebago Vectra Diesel Pusher and I'm having trouble with the lights not working off the coach batteries.

I can get all appliances and lights to work when I'm plugged in, but not when it's unplugged. All batteries are hooked up correctly and have ample volts.

I don't know if the converter has something to do with this or not. The converter is in a bad place to get to, so all I can see is the back and side.

I should also add that when I'm plugged in to shore power the batteries are not being charged.

I have had this problem for a while now and I'm getting tired of putting in batteries every year.

Any ideas?

[dickandlois]

Jlacaeyse,

Welcome to FMCA !

Sounds like a possible transfer switch or fuse issue. With the 12 volt lights working when on shore power means the charger is working. Look for a large fuse between the batteries and the charger 12 volt output feed to the positive coach battery terminal(s).

With a meter you should read a voltage at the positive terminals. They will read very low if no charging voltage is present.

The house batteries (as well as chassis batteries) should charge when the engine is running, if not then you should find a fuse in a positive 12 volt feed between them and the alternator.

Check all the wiring to see if its correct, you might need to find a little help if your not familiar with the circuit. With 12 volts present when the charger is running when on shore power, one would suspect there is a wire routing issue, as you should get 12 volts from both the charger and or the batteries if things are connected properly.

I have a feeling that you do not have 110 volts from the inverter output when you are not connected to shore power.

Hope this gets you started in the right direction,

Rich

[wolfe10]

Let's start at the beginning of the 120 VAC system: Because you said "all appliances are working when plugged in", you can conclude that: Shore power cord, ATS and power to main 120 AC breaker box is OK, as are at least some of the breakers and the wiring from them to their appliances.

First check is that the 120 VAC breaker for the converter is ON. Yes, some older coaches had only a fuse in the converter itself, and no breaker. Anyway, verify that the converter is getting 120 VAC.

Record the voltmeter readings at the battery (I would do this for BOTH chassis and house batteries):

Battery at rest, no shore power and engine off:

Shore power on:

Engine on:

Let us know what you find and we can go from there.

Brett

[jlacaeyse]

Thanks all for the replies.

I will check into this tonight or first thing in the morning and get back on with my findings.

[jlacaeyse]

Ok, I did some research on my coach.

The batteries not running are all 12.58

The Chassis battery running is 14.35

The Coach batteries running stay at 12.58

Plugged in not running the Batteries are at 12.58

I checked all fuses and breakers and everything is ok not tripped or blown.

I then located the converter and tested the volts coming out and they bounce between 11.2 and 13.5 which didn't seem right to me?

[wolfe10]

I'LL REPLY IN SOLID LETTER CAPS

OK, I did some research on my coach.

The batteries not running are all 12.58. ASSUME YOU MEAN WITH NO SHORE POWER AND ENGINE OFF-- THAT VOLTAGE IS OK-- ABOUT A 40% DISCHARGED BATTERY.

The Chassis battery running is 14.35. VERY GOOD-- THAT IS WHERE IT SHOULD BE.

The Coach batteries running stay at 12.58. PROBLEM. THAT MEANS YOUR BATTERY ISOLATOR (COULD BE DIODE-BASED OR SOLENOID BASED) IS NOT WORKING. BOTH BATTERY BANKS SHOULD BE CHARGED BY THE ALTERNATOR.

Plugged in not running the Batteries are at 12.58. WITH THAT READING ON THE HOUSE BANK, THAT MEANS YOUR CONVERTER, CHARGER OR INVERTER/CHARGER IS NOT WORKING. SOME COACHES ALSO CHARGE THE CHASSIS BATTERY, BUT MOST DO NOT.

I checked all fuses and breakers and everything is OK not tripped or blown. SEE TWO SEPARATE ISSUES ABOVE.

I then located the converter and tested the volts coming out and they bounce between 11.2 and 13.5 which didn't seem right to me? CHECK ALL WIRING CONNECTIONS. IF OK, I AGREE THAT THE CONVERTER IS NOT WORKING.

[jlacaeyse]

Do you happed to know where I can find the isolator?

[wolfe10]

Trace the large positive wire from the alternator. It will go to the isolator. There will also be large-gauge wires from isolator to chassis and to house battery banks.

Most are in or near the engine compartment.

[jlacaeyse]

Well after a long night I have finally figured out that it was a bad AUX Battery switch on the dash not allowing it to open up the circuit. After fixing that plugged in I had 13.4 volts to the coach batteries and when the generator is running.

Now still when the engine is running it's not charging the coach batteries. So I'm going to try to find the isolator and see if that's the problem.

I'm getting closer!!! Thanks for the help.