BAC Forum
General Boards => Technical Support => Topic started by: Carl Boger on February 06, 2024, 10:59:35 PM
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To shorten a long story my alternator went out after being jump started at a windshield repair shot. They kept it longer than planned and the voltage dropped low taking out the alternator. It could have been plugged in to charge the batteries, but wasn't. In a attempt to fix it the tech got the wrong alternator and also Wired it up backwards. This took out the 12 volt charge wire that had to be replaced as it grounded it and melted the wire. It also took out the 12 volt ignition wire, as there is no longer 12 volts on it.
To get the coach going I found a relay That had a switched 12 volt spare terminal and ran a new wire to the new/correct alternator. The motorhome now charges as before but if possible I would like to return it to the stock confuguration.
So does anyone know where the white wire that goes to the alternator ignition terminal start at? Is it fused anywhere? I have looked over the wiring diagrams but haven't been able to find what where it might be, but my computer doesn't let me enlarge them enough to see everything.
Thanks for any help. I know it is fixed now, but would like to fix it better.
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Carl
The alternator ignition feed comes from the service bay panel it is teed into the ignition power feed at the front rear control switch the power is coming from the front electrical bay circuit breaker #21 for the ECM ignition as shown on page 18 of the 1996 Patriot wiring diagrams it passes through several connectors front the front of the coach to the rear.
Hope this helps
Eric
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Thanks Eric,
I seem to have lost the 12 volts somewhere, but do still have it up front. I guess I can leave it this way, but If I can find the connector that is loosing power I will probably fix it to the factory setup.
I actually started looking at the circuit breaker in the front electrical bay. I have 12 volts there, but don't have it at the alternator. Hard to follow the wire inside the harness and around the engine.
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Carl
would the engine start and run from both front and rear controls before you bypassed the ignition feed to the alternator?
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It would start from the front, didn't try the rear. Problem was it would not charge, but can see where the rear start also meed the ignition 12 volts
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To follow up, went out again today and started at circuit breakers 21 and 22 and took them loose and wiggled them back and forth. The wire were clean terminals were clean and I reattached them.
I went to the alternator and found where the mobile tech had snipped the ignition wire and reattached it with a butt connector and shrink wrap. I checked the voltage and got 10 volts. I decided to try it on the alternator so I removed the jumper ignition that I had made up and cranked the MH. The alternator was charging right at 15 volts, and it is a 15 volt alternator.
I let it run for a while and it charged as normal the whole time. I then went back to the ignition wire at the alternator that had just tested at 10 volts and I am currently getting 12.6 volts.
I have no idea what I did to correct this except maybe the line had static in it from being hooked up wrong and a fresh 12 volts helped clear it. Hopefully his will continue to work. If not I left the jumper ignition inplace and made sure the end was taped over so it couldn't ground out.
Not to sure how much this will help someone in the future but did want to follow up.