I bought an 86 IROC earlier this year and the wiring harness has been hacked beyond belief. Someone literally took 2 or 3 rolls of red 16 gauge copper wire and rewired everything in the car, complete with multiple splices and duct tape holding some of the wires together. Needless to say its a mess.

My problem at the moment is the altenator is not charging the battery. I believe its because the internal voltage regulator is not functioning and may be wired wrong, or maybe something came loose. Can anyone help me figure out exactly where those 2 wires that come out of the electrical connection on the top of the alt are supposed to go? Right now they go into what looks like a relay of some kind.

If it helps the car is a 305 with an edelbrock single plane on it now. Im unsure if it was a TPI car before the hack job. Can you tell by the VIN? the RPO's are long gone.

 

After searching a bit i found some useful information but im still not sure about 1 wire. The problem is im inexperienced with electrical terms and systems and i dont understand what is meant by "switched V source." Can anyone put this in plain terms that a dumb hillbilly like me can understand please? Im assuming this means a power wire that is only hot when the ignition is on..... does there need to be a resistor or anything in line?

The post i found:

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It sounds like your exciter wire is not getting the voltage feed back it needs.
I had the same fun your haveing a couple of months ago.

the big wire off of the back of the alt. should go to the battery or the main (big) terminal on the starter. (obviously)

plug on alt has 2 wires

big red wire goes to same place as the previous wire

the other wire (maybe white) is the Voltage sense wire ( alt won't charge without it)
this one is a switched V source.
Just to test you can connect a wire from your battery to this wire with a small resistance in line (wire a bulb in there ) and you should see 13 - 14 V at the battery.

This wire was my problem ... I couldn't find the source of the break (and have a better wireing harness in a parts car that I plan on transplanting soon ) so I did a stupid splice job into my hot wire at the distributor. I wouldn't have done it this way if I didn't plan on ripping it all out this spring (P.O. hacked the existing harness badly ... and must have gotten a good deal on 14Ga. GREEN wire, 'cause I've got dozens of green wires under the hood)

hope it helps
Tony

 

 

Thanks, i got it wired up today and it was holding a steady 14.5v but after 20 mins of running it dropped below 14, to about 13.6, with no change in any of the electronics to justify the drop. It was gradual as well, not like an all of a sudden drop. How much voltage fluctuation is normal?

 

 

Thanks for the help. I just took the car for a short drive and on coldstart it was just over 14 and stayed there for the 10 min drive. I think its fixed. Thanks again for the help.

 

do you have pics of how you did yours? im having the same prob.. i have the wire coming from the back of the alt straight to the battery. i have the 3 wire plug (blk/wht/red) going to alt. have new alt and battery and wong hold charge. where do they go to? i know one wire goes to gauge but which?.

 

 

Does anyone have pics of where the wires go to. Myy bay is a mess and everything is spliced and taped up.

 

I could take a picture of my splice job but i doubt it would help. First of all my car was badly hacked and none of the wires are original to the harness. They are all red wire bought from a local hardware store or something. Don't ask, i'm not sure what the guy was thinking. Also my alt is a 2 wire plug so its probably different than yours.

Ill tell you how is wired now but like i said its a different alt than you have so its more than likely different.

The large red wire coming out of the plug got spliced into the main cable coming off the back of the alt directly to the battery. The other wire (green and white? im colorblind) was spliced into a switched power supply. In my case it got wired into the electric fans so when i flip the switch for the fans, the alt charges as well.

I know my "fix" sounds really ghetto but it is a soon to be stripped down race car and everything is wired to toggle switches so im just keeping it going until my new motor is finished and i redo 90% of the car.

Hope this helps

 

Hey Ian,

Check your PM.

 

Took me a couple days but replied.....