1994 Coronado electrical issues

[Tmac1515]

Working on a family friends Coronado. I'm not a professional mechanic but the gentleman needs cheap labor. The owner went to replace the 2 6v batteries. He wired them up backwards and caused issues. I had to replaced the cap and rotor and that made it run. But I'm still having weird electrical issues. The battery gauge is reading low even though batteries and alternator tested good. Alternator fuse is good, but doesn't seem to be charging. Coolant temp sensor isn't reading. Headlights aren't working and the blinker/reverse fuse keeps blowing every time its used. I've tested all other fuses and breakers and they seem to be in good working condition. I'm not sure if this could be a fried computer problem or what.

I'm looking to see if anyone else has a wiring diagram or even had similar issues with a good idea of where I should start.

 

[bigb56]

The chassis actually uses two 6 volt batteries or are you confusing the house battery system with the chassis system? There are two separate battery systems.

 

[Kirk]

The 1994 Fleetwood Coronado was a Class A motorhome produced by Fleetwood RV. It was offered in various models, some of which included the M-30H on a Chevrolet chassis or a Ford, F53 chassis. Am I correct to assume that it was the chassis batteries that he was replacing? The two 6V batteries in series sounds much more like the coach system than it does the chassis battery as most of those have one, 12V battery to start the engine. If you have a GM chassis and it was the starting battery being replaced, there is a P-30 manual that can be downloaded. It it has an F53 chassis, you can probably get some information from the Ford website but I'm not sure how much.

 

[Tmac1515]

Apologies. I tried to change the post but it was too late. The owner made it sound like it was the coach batteries but with some more questions I was able to clarify that it was in fact the 1 12v chassis battery that was miswired. This better explains the issues being related to the chassis itself.
I appreciate the P-30 manual that you sent over. I will start troubleshooting based on that diagram and see if it gets me anywhere. I'm sure I'm going to be looking for a short in a wire somewhere or maybe an isolator.
Thank you for your help.

 

[CharlesinGA]

Reversing battery polarity on a charging system with an alternator will instantly blow the diodes in the alternator. You will need to remove it and have a shop test it.

Charles

 

[Chef Duane]

Was it the Coronado or Cordoba that had rich Corinthian leather?

 

[Gary RV_Wizard]

Was it the Coronado or Cordoba that had rich Corinthian leather?

LOL! Ricardo Montalban made that phrase iconic.