Strange electrical problems in the 86 FJ60 (carb fan & charging) (1 Viewer)

Joined
Nov 5, 2021
Messages
23
Location
Austin, TX
Figured I would share this fix:

First sign of problems came with a dead battery. It was aged and wouldn’t take a charge so new one went in. Then the new battery kept draining. So I get the alternator checked out. Alternator tested bad. I wasn’t sold on that since it was recently rebuilt. Then I noticed my carb fan wasn’t blowing. So I test for shorts... checked fuses and no current draw on meter. I was stumped. Thought on it for a day and started checking wiring around battery and alternator. When grabbing the wiring close to the alternator I heard a relay click. Found the short. Replaced all wiring between the battery and alternator and spliced into the wiring harness very close to the loom.

After the fix the carb fan started blowing again and also key In ignition door chime came back. I hadn’t heard the door chime in like a year. Not stoked the chime is back lol

Most all material on here about carb fan malfunction is associated with the bad temp sender that should be grounded. That was not the issue.

There are two hot wires that come off the alternator. 1 to the battery and one into the wire harness. That was the shorted wire. I don’t fully understand why this effect happened based on wiring diagrams. Other than a battery drain I didn’t notice any other issues.
 
Joined
Oct 30, 2007
Messages
10,343
Location
Plano texas
Hi ,Bad wiring does all kind of crazy feedback things. Just found this out again with my fj62 and Mercruiser. If your negative earth ground to body and engine is old get rid of it,your whole electrical system will thank you. Yeah things will work on the old ground wire just not good,esp your head lamps. Mike
 
Joined
Nov 5, 2021
Messages
23
Location
Austin, TX
Hi ,Bad wiring does all kind of crazy feedback things. Just found this out again with my fj62 and Mercruiser. If your negative earth ground to body and engine is old get rid of it,your whole electrical system will thank you. Yeah things will work on the old ground wire just not good,esp your head lamps. Mike
I rewired all around the battery this morning.

Cut out the fusible link and created a fuse box setup and fresh ground cables. Its a little crude, but it works great. Good voltage across it. Could definitely be a viable fix for someone with a bad fusible link at the battery. I have one 14 gauge fusible link wire that provides protection for the alternator and feeds the fuse box. The fuse box has four 40 amp fuses to protect the wiring harness feed and my aux power for radio and a few accessories. Should be fine because no winch or high amp things on it.

Maybe I should create a separate post for this.
 

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