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Topic: 12V -side question (Read 2879 times) previous topic - next topic

Re: 12V -side question

Reply #60 –
Certainly a good test to charge, disconnect, and test the resting voltage of the batteries but I have been wondering about the battery cables.  We all know to keep the ends clean for good continuity but that is really only half of the connection.  The other half is the crimp inside to the wire which you cannot see.  It's quite possible that sometime in the past 20 years these cable ends got pretty covered with acidic battery deposits that may have worked themselves inside to the crimp area.  Cleaning would only remove the exterior deposits and combined with time a high resistance maybe the result and this does fit the symptoms.  So once you reconnect the batteries back up, check for a voltage with a meter connected with one test lead on the battery and the other at where the cables terminates -which would be under the white cover on the wall that is to the left of your batteries.  You will need to check both the positive and negative cables.  If access to the other end of the cable is difficult you can also just use a needle probe (or safety pin) on the voltmeter to poke through the outer jacket of the cable.  Hope this helps.

Re: 12V -side question

Reply #61 –
John, that thought has been going though my mind some, too. The best solution would be to replace every cable and end with all new, but that isn't going to happen. What gets me is that all was working fine the last time we drove the coach, and now it doesn't work.

Re: 12V -side question

Reply #62 –
Kb0zke,
Great time to get the wiring diagrams out along with a reasonable DVM and start trouble shootin, surely the problem will appear under  normal situation when it worked before.
Should be reasonable to locate where it fails. ?
Sounds like a fun challenge.

Re: 12V -side question

Reply #63 –
FWIW
For the last few days I have been wondering if when you tested your battery voltage you also tested from + battery post to frame of coach.
Seems like that would go some way toward telling you something about the cables.

Re: 12V -side question

Reply #64 –
Quote from: TheBrays –
FWIW
For the last few days I have been wondering if when you tested your battery voltage you also tested from + battery post to frame of coach.
Seems like that would go some way toward telling you something about the cables.
As well as a resistance check from the battery negative to chassis ground.

Roland

Re: 12V -side question

Reply #65 –
FIXED!!! The schematic above shows three fuses, and I found only two under the white panel. The third one, it turns out, is located underneath the converters/chargers. One of the leads was somewhat loose. I tightened it up (power was off), turned the power back on and all looked good. Then I flipped the 120VAC off and the furnaces kept running. Lights were on in the bays that were open. Problem solved - I think.

As I think about it, I may want to add a lock washer to that connection, but that can wait for a warmer day.

Thanks to Kent Speers who helped point me at that connection. I had assumed that because the 12V stuff worked when plugged in all of the converter/charger area was find. Not so.

Re: 12V -side question

Reply #66 –
David,

Great! If you have a camera handy, please shoot a photo of the location and post it. Sure would be easy for anyone to miss. Good job.

Pierce

Re: 12V -side question

Reply #67 –
Will do. It is 50 and sunny out, and we're going to straighten out the bays a bit, so it will be easy enough to take a couple of pictures and post them this evening.
 

Re: 12V -side question

Reply #68 –
Here are a couple of pictures. One shows the two chargers/converters sitting on the shelf where the old "battery cookers" sat. The other shows the missing breaker underneath the shelf.