Forum Discussion

2Bargos's avatar
2Bargos
Explorer
Mar 26, 2015

Alternator Issue

A few days ago I went to my motorhome (ford f53) intending for its Monthly exercise ,I noticed When I started it up that the alternator was not charging. I though okay no problem I'm in the rebuilding business so I'll take alternator off and to my shop and rebuild it.

I removed the unit and when I bench tested it the output was fine. Since the unit was the original 96 model and I already had it off I decided because of its age to redo it anyway.

After I reinstalled it I still had same problem, after some trouble shooting I noticed that the battery light was not coming on when key was in run position.

I checked all the fuses and all were good so on to next step.
Tested Main battery wire on rear of alternator for voltage and it tested at 12 volts so that's good

After much testing and wire tracing I found the problem. The alternator activation wire( wires that goes into plug on alternator) runs across top of fan shroud and makes a sharp bend at top left of dog house runs into dash wiring harness.

Something I have yet to find had cut the wire. I put the wire back together and now everything is working fine. I'm still trying to figure out what cut the wire.

Sorry for being so long but Over time I've read a lot of post about problems others are having and they never reply with the solution.

Hopefully if someone else runs into a similar situation this may help
  • Gjac's avatar
    Gjac
    Explorer III
    When my 110 amp alternator failed 8 years ago I replaced it with a rebuilt 180 amp one. I has worked fine and then I installed an ammeter/voltmeter with a shunt to measure amps and volts to the house batteries. I never measured more than 7 amps going into a 50% discharged 2 6 volts GC batteries. After reading your post I wonder if some strands of wire were chewed or worn through reducing the amps going into the batteries. I would assume I should see more than 7 amps under those conditions. Something else to check.
  • I wonder if it was cut, chewed, wore through, or aggrivated to breakage?
  • Thanks for this information!

    I might be able to use it soon! I am also having problems with my 97 Bounder on a Ford chassis. I have not had time to look into it yet, but will soon. It will be in storage for the next few months, and I will look at the wiring before removing the alternator.

    Thanks for the tip!

    Fred.
  • Well Sir,
    The mere fact that you found the problem is great. Now, based on your experience and, your capabilities, and analytical skills, are you DEFINITELY sure that, the wire actually "CUT" and not just sort wore through? Is it possible that a rat had chewed through it? We've all heard of and read of, those critters chewing through wiring and wreaking all kinds of havoc on our parked coaches.

    It (that wire) makes a "sharp bend" at a certain point you say. Is it possible that, at that sharp bend, it just couldn't take it anymore and gave up the ghost at that bend? Just wondering here. Good luck and good job on getting yourself going again.
    Scott