12v converter problem?

deallaw · 04-04-2012, 10:49 PM

I'm having a strange elrctrical problem and suspect the converter is going bad but want to make sure before I replace it. When I switch on a 12v light in my 2010 Winnebago Vista it occasionally knocks out the entire 12v (and sometimes 120v) power. It doesn't trip any 12 or 120v breakers but when I turn off all the 12 v lights, turn off and then on the main 120v breaker, power is restored. I checked the batteries and they read about 12.5 volts. A tech suggested I listen for a fan on the converter to see if it's working - if not it could be causing the converter to overheat. I think the converter is behind the breaker panel but not sure. I don't have an inverter on the coach and the manual says it's a Schumacher converter but not much additional detail. I would also note the 12v lights are a little dim so maybe it is just a bad cell in a battery, but I don't understand why that would cause everything to shut down when connected to shore power. Anybody ever encounter a similar problem or have any suggestions? Thanks!

Dave78Chief · 04-05-2012, 09:15 AM

Is this the FE32K model? Do you have 30 amp shorepower service or the optional 50 amp service?
One thing to try is turn off the converter at the AC distribution panel (Fridge/Converter on same AC breaker) and see if the problem is there when using just the battery as the 12VDC power source. Looking to see if it only happens when converter is ON.

FE32K 110 wiring diagram: http://www.winnebagoind.com/diagram/...ire_172656.pdf (reflects both 30 amp and 50 amp styles of service so make sure you use the correct one.)

FE32K Electrical Parts locations: http://www.winnebagoind.com/service/...k_electric.pdf (converter on pdf page 16)

Dave

deallaw · 04-09-2012, 10:33 PM

Thanks Dave. Yes I have a 32k with 30amp. Good suggestion turning off converter at the breaker panel. When I turned it off and put a few 12 volt lights on, the battery voltage dropped from 12.5v to 5v. The I turned the converter back on and checked the battery terminals (leads still connected) and they read 12.5v, so it looks like the converter was trying to charge the batteriies. I assumed there was a bad cell(s) in the batteries and was ready to replace them. But we still had a couple days at Disney World so I thought I'd wait. Drove to the next the campsite, hooked up to shore power and the 12v lights worked fine. Ditto next campsite 400 miles later. I tried turning off the converter and turning on all the 12v lights, checked the batteries and they read 12.5v after 30 minutes. So could I have had a bad 30amp connection at ft wilderness Disney? Or is this just the start of the converter or batteries going bad? I'm inclined to take the batteries out and bring them to napa to have them properly tested. Thanks again for the suggestion and link to the wiring diagrams.

Dave78Chief · 04-10-2012, 08:24 AM

Have the batteries tested plus go through and dress the battery cables. The intermittant nature does point towards a cable problem. Could be a positive or a negative lead. A cable can look OK externally but can be bad inside the lug or battery connector. You may be making the cable make connection by moving them around.

Dave

John Hilley · 04-10-2012, 09:09 AM

It could still be a converter/charger problem. The engine alternator would have charged the batteries on the drive between campsites. It may be after you are at a campsite without the converter/charger working right that the problems starts.

FDchief · 04-10-2012, 09:34 AM

A couple of things to ponder. Firstly, your converter really has nothing to do with your 110V outlets. It only takes in 110V and converts it to 12V. These two systems are unrelated other than the feed to the converter. So if what you were saying about losing power to a 110V outlet with a light on it, I would suspect your campsite power. But if at the same time you significantly had dimming of your lights, I would say that you could have a bad solenoid that is not charging your batteries on your coach when connected to shore power. Very common on Winnebagos. Easy to test; just use a multi-meter and with the engine off and the battery disconnect "on" read your voltage on your batteries. Should be around 12.6 if you have just driven the coach. Now plug your shore power in, you should see between 13.4-13.7V. If you don't it is time for a new solenoid. This is the same solenoid that allows you to hit the switch on the dash that allows you to power the chassis battery from the coach batteries if your chassis battery is dead.

Lastly, your converter fan should not run all of the time. It only runs when called for due to internal temps of the converter.

John Hilley · 04-10-2012, 10:04 AM

" I would say that you could have a bad solenoid that is not charging your batteries on your coach when connected to shore power. Very common on Winnebagos. Easy to test; just use a multi-meter and with the engine off and the battery disconnect "on" read your voltage on your batteries. Should be around 12.6 if you have just driven the coach. Now plug your shore power in, you should see between 13.4-13.7V. If you don't it is time for a new solenoid. This is the same solenoid that allows you to hit the switch on the dash that allows you to power the chassis battery from the coach batteries if your chassis battery is dead."

This isn't exactly right. The solenoid is a battery isolation switch that connects the house and chassis batteries with the engine running and separates them when the engine is off. Regardless of whether the solenoid is good or bad, you should see about 13.2 vdc on the house batteries when on shore power. If the solenoid is bad and the chassis battery is bad, it could pull the converter/charger voltage down.

deallaw · 04-10-2012, 09:40 PM

Thanks for the advice everyone. We're back home now so I have a few weeks to experiment before our next trip. I'll definitely brush the battery posts/cables and have the batteries tested. I should have mentioned that even though the 12v lights were bright our last two nights we did notice them flickering a little. I also read about a problem with the "salesman switch" on another thread - I think that's the coach kill switch near the stairs to make sure the batteries don't drain while in storage. This switch did trip off when the 12v power went out.

I need to bring out my digital meter next time, I don't think it ever read over 13v when connected to shore power but can't be sure with the old school meter I was using.

DAN L · 04-12-2012, 02:49 AM

Quote:

Originally Posted by deallaw

Thanks for the advice everyone. We're back home now so I have a few weeks to experiment before our next trip. I'll definitely brush the battery posts/cables and have the batteries tested. I should have mentioned that even though the 12v lights were bright our last two nights we did notice them flickering a little. I also read about a problem with the "salesman switch" on another thread - I think that's the coach kill switch near the stairs to make sure the batteries don't drain while in storage. This switch did trip off when the 12v power went out.

I need to bring out my digital meter next time, I don't think it ever read over 13v when connected to shore power but can't be sure with the old school meter I was using.

check these resources:

Electrical Tutorial

Batteries -- and Other Electric Stuff by phred

deallaw · 10-28-2012, 05:30 PM

A belated follow up on this. Batteries tested ok at autozone but I decided to upgrade to group 31 AGMs (2 exide 200s). The OEM Schumacher Converter was the source of the problem, so I replaced it with a ProgressiveDynamics 70amp unit and it's a big improvement. No problem with 12v system since. Thanks all for your feedback and help.