Unusual 12v issues

MH Mike · 09-23-2011, 10:38 AM

Hello All,
I just purchased a 1999 Adventurer Model WG37G. In familiarizing myself with the coach I noticed some of the 12v issues.
First off the house batteries do not charge with shore power or generator but they do when the engine is running.
The 12v items in the coach do not work on house batteries but do work on shore power or generator.
Additionally the previous owner hooked up an inverter that has 2 batteries wired in parallel with ground to chassis and positive hooked up to the front lug on the generator. With the inverter hooked up this way I get 12v to the coach.
I have repleced the house batteries, checked the converter which works on shore power and putting out 13.6 v to the batteries. (the batteries are registering 12.6 volts). Any suggestions or recommendations? In lieu of suggestions I would welcome a referral to a qualified RV tech in Temecula.

texnet · 09-23-2011, 11:49 AM

I am a little confused as you state you have 12v to the coach with the inverter that the previous owner installed... an inverter is used to create 120vac from 12vdc so the only way that you are getting 12vdc to your coach with the inverter running is the inverter is supplying 120vac to a converter which then changes the 120vac to 12vdc.....

As for your batteries not charging... most coach converters are also chargers so it is possible that your converter is just a converter and not hooked to the batteries... However, you state that the converter is supplying 13.6 volts to the batteries... if this is the case then the batteries are charging...

Can you draw up a schematic of what you have so everyone can see the big "picture"?

Dave78Chief · 09-23-2011, 12:29 PM

Battery disconnect switch (2nd switch from the bottom to the right of the steering wheel) is either in the disconnect position or the disconnect relay is bad.

Main wiring diagram launch page for your rig: Table of Contents

Disconnect relay wiring (page 2): http://www.winnebagoind.com/diagram/1999/131000.pdf
Disconnect relay (bottom one) is opereated by the dash switch. When in disconnect the lights will not run of the battery nor will the converter charge the battery. COnnection from it to the coach battery is shown on the 12VDC body diagram (page 2): http://www.winnebagoind.com/diagram/1999/131001.pdf

Solinoid is your house battery - chassis battery cross connect relay which is operated by the Aux start switch on dash (left of steering wheel). When energized, it allows you to use the house battery to assist starting the engine or charge the house battery when the engine is running.

Disconnect relay has to be ON in order to allow converter charging voltage to reach house battery

You drawings are a little confusing but you need to use both the 12 Volt body and automotive drawing to see how the battery disconnect and solinoid is connected. Additionally, the automotive diagram there are both Chevy and Ford as well as early (99) and late (99.5) versions of each for your rig. Can be a bit confusing shall we say.

MH Mike · 09-23-2011, 02:32 PM

Thanks for the replies and suggestions. I will try as best I can to answer yor questions-

Textnet
I suspect the inverter is somehow feeding the house circuit through the 12v connection at the generator. There is nothing plugged in to the ac side of the inverter and the inverter is turned off. With respect to the converter it is outputting 13.6 volts but that is not making it to the batteries. I will try and make up a schematic.
Dave
The position of the dash switch makes no difference in either the charging of the house batteries or 12v house circuits. I do suspect that there may be something amiss with either the disconnet relay or possibly the transfer switch. Still trying to figure out how to test these.
Thanks for you help-Mike

Dave78Chief · 09-23-2011, 05:55 PM

First step is you need a voltmeter or at least a 12VDC trouble light.
Disconnect the rig from shore and generator power Aux Start OFF battery disconnect in disconnect. Based on the prints, when looking at the relay, you should have 12VDC on left side large post to ground and 0 Volts DC to right side. Set Battery Disconnect to Connect. Should see 12VDC on both large posts and your 12VDC lights should be working.

Here is a link to a discription about how a typical disconnect relay works. (http://intellitec.com/PDF/5300066.100.pdf) Simply put, only a momentary signal is applied to the relay to make it shift (not a constant voltage). That way the battery does not get drained down when on. The polarity of the 2 control posts is reversed to open / close the relay (momentary signal).

Solinoid (Aux start) does have constant voltage applied to small terminal to energize it. No voltage to small terminal and it is not energized.

Dave