Hacked wiring

[laidbackbigun]

Okay so on my new to me 95 tahoe with 5.7 the previous owner cut down the plug that goes into the back of the alternator. I believe the only wire he saved was to the gauge because it works. Overcharged but works. What would the other 2 wire goes to.

 

[iamdub]

Probably the wires from the PCM that controls the alternator's output regulator. You should fix that cuz batteries don't like to be overcharged.

 

[laidbackbigun]

Well I can get a new pigtail but that doesn't help if I have no idea where the other wires go. All the wiring diagrams I have found are for older 1 wire alts on prior 5.7l

 

[iamdub]

So, you have a one-wire alternator now?

I'd get the correct alternator for the truck then go cut a pigtail from a salvage yard. Match up the wires and solder and heat-shrink them together to make it like stock again.

 

[laidbackbigun]

No I have a 3 wire alt and a 3 wire pigtail. Previous owner clipped 2 of the wires about 1/4 inch from pigtail and somewhere back along the harness. I don't know why.

 

[iamdub]

No I have a 3 wire alt and a 3 wire pigtail. Previous owner clipped 2 of the wires about 1/4 inch from pigtail and somewhere back along the harness. I don't know why.

Lame.

 

[Kenny D]

Well I can get a new pigtail but that doesn't help if I have no idea where the other wires go. All the wiring diagrams I have found are for older 1 wire alts on prior 5.7l

Buy a Chilton's manual for your vehicle, they have extensive wiring diagrams.

 

[Kenny D]

Or you can peel back the harness and match the wire color, I would bet that the dipwad probably didn't go too deep into the harness to clip them

 

[Kenny D]

Don't know if you have done anything yet but looking at the wiring diagram it shows a blk/red that goes to the positive terminal on the battery, then there is a brown wire that goes to the gauge, the white wire is for diesel only. No other wires are used. The voltage regulator should be built into the altenator. The diagram I am looking at is from section 12-39 in the Haynes manual for 1988- 1999 full size and suv. ISBN 1 56392 426 9 799-1158

 

[laidbackbigun]

I saw that to. So it has 2 wires running to battery?

 

[Kenny D]

I saw that to. So it has 2 wires running to battery?

No the wire should be red with a black stripe, or maybe just red.

 

[laidbackbigun]

There is a 8 gauge wire going to the charge lug on back of alternator that runs to the battery. The connector also has about a 12 gauge red wire coming out of it.

 

[Kenny D]

Then the wire from the plug must go to your gauge. According to the diagram, that is all that is there. If you are overcharging then the regulator in the alternator is going bad. Just how high is it charging? All the way to 19 or somewhere closer to 14?

 

[laidbackbigun]

Well b3fore I started taking everything apart to fix this beast the gauge would sit around 17 8 never hit it with a multimeter. Stupid me. I was hoping to wire this thing back up correctly and go from there ha

 

[PG01]

There was prob an issue with the factory wire in the loom somewhere or it wasnt charging enough so he ran a wire direct from batt to alt, i used to do this on all my plow trucks, especially the older ones.

 

[Kenny D]

Can you take the alternator to Autozone or other autoparts store, they can test it and tell you if it is going bad.

 

[laidbackbigun]

I probably could do that.