1981 fj40 alternator wiring (8 Viewers)

[Buffchief]

I have an alternate from an 1985 fj60 with internal regulator installed in my 1980 fj40 with a 1981 wiring harness. My problem is that I had the alt rebuilt twice because of of one thing or another in the past 3 months. Both times the voltage regulator is burnt out. The alt specialist shop is scratching his head and said he thinks the yellow "L" wire may be back feeding into the alt and suggest cutting it or just disconnecting it in the harness. He said it was just used for a warning light ?!? Wasn't sure. Is he wrong? I don't want to fry this voltage regulator also! Or should it be the black with yellow wire?
Thanks

 

[charliemeyer007]

Have you consulted the wiring diagram for the host model/year and whatever you have in the rig?

I suspect if it burned out twice so far and you hook it up the same failure 3 will be soon enough. Have you check the wires - in 40 years maybe a spot is worn threw the insulation and is now an intermittent short which can be very hard to find sometimes.

For me when my 35 A alternator (OE) goes or its external voltage regulator (replaced by me at least once since 1982), I'm going with a GM one wire 90 to 140 A alternator and just monitor the voltage instead of the A. A correct pulley fit is important Should cost less than $150 to bolt on.