3G wiring confusion.....

[35Remmy]

Ok guys, truck is an '88 2.9L....the stock alternator "D-shaped" plug has 2 wires, one that is green/red striped and the other that is BLACK/YELLOW STRIPED. The only info online i can find, including schematics, is that this black/yellow striped wire is "supposed" to be yellow/white. I dont want to wire up this alternator incorrectly!
The other rectangular plug also has 2 wires.....one BLACK/YELLOW STRIPED and one black.
Idk if this truck is different because it is an STX with a light bar/lights and fog lights from the factory and was wired differently??
In any case, the "painless" 3G harness im trying to use has a green/red striped wire and a yellow/white wire.
Any help would be greatly appreciated.

 

[RonD]

Should be fine with that wiring, assuming you have a VOLT METER on the dash not an AMP METER

The green/red wire is Battery Light wire, runs to dash, its the ON/OFF switch for alternator

Black/yellow should be hooked to battery positive as should the other black/yellow and black wires
Use a volt meter and test that all 3 show "battery volts"
Test battery first then test each wire should be exactly the same volts, key off or on doesn't matter
These 3 wires use fusible links attached to starter relay on inner fender, where battery positive cable is attached

Green/red wire should only show 12v only with key on
If you want to test that, which you should, because you are replacing alternator for a reason, lol

An alternator has no Ground wire, just the metal case is all the ground it needs

Yes, in 1988 that one black/yellow wire with the green/red wire should be a yellow/white wire
And the other two wires should be black/orange, so not sure how these changes happened

 

[35Remmy]

Ron thanks a ton for sharing....i wired it up accordingly....this is a 5.0 conversion so i cant "test" her out yet

 

[holyford86]

an additional suggestion I have would be to add an additional heavy gauge wire from the output stud directly to battery positive (this would be where the black/orange wires would be connected to)