my alternator has quit charging every since i took out the TBI wiring harness and i think i may have taken out one of the wires.
On my alternator (88 camaro) it has the main power wire, but then it has a 3-wire connector. I know where the red and brown wires go and what they do, but the third wire is a tan wire. The wiring diagrams dont show a third (tan) wire. I was wondering where the tan wire goes and what is it for?? Thanks in advance.

 

TTT

 

i think the one your refering to is the wire that gives juice to the alternator. my alternator was giving me problems and i had it wired up all wrong. there should be one wire to the battery, one to a power source that is hot when the key is on and the other wire goes from the alternator back to the alternator. hope you understand. someone else will answer with the technical terms and probably help you more.

 

The tan wire is the alternator sense lead. It normally goes to the circuit that feed the blower motor. What it does is feed a sample of the voltage from the point in the car that has the largest voltage drop. This is done to try to provide a good 13-14 volts under high demand. You can basically tie it to any place that has 12 volts, but I would recommend it be a place that is ignition key controlled. To test charging simply feed the voltage from the wire next to it (brown) or the red if you want. Your alt should then come up.

 

is that tan wire a must? I am finishing up my V6 to V8 swap. All i have to do is wiring. I put the old style two wire alternator on. There is a black wire that comes in from the fuse block, i think thats for the gauge, then there is a red wire that goes to the little post on the alt, then a wire that goes from the little post to the battery. I eliminated the tan wire. HOWERVER that wire goes to the electric cooling fan relay(it probably goes other places too if it is supposed to notice a voltage drop)I cant get my fan to kick on, but will not fill this post up with my questions.

 

I am a little confused as to which alternator you have. Anyway, the tan wire can go to any place that has 12 volts. On single fan models it generally goes to the place where the fan relay gets it's voltage. If you are doing a conversion I would recommend a Chilton manual for the wiring. Reason is that how the fan is controlled is different between the different engines. If you give us more info we can help.

 

ok let me ask this, does the tan wire give the relay power? i know there is the huge red wire that gives the fan power, but the relay has to have power to work itself right? and if its hooked to the alt, it will only have power when the key is on? is that right? thanks, wiring is not my thing, but i am getting better at it. :lala:

 

No it should not provide voltage. The voltage for the coil side of the fan relay gets it's power from the fuse panel in the car. It is a key on voltage. The sense wire simply ties into that circuit to sample voltage drop when the fan comes on. The relay will have two heavy wires that provide voltage to the contact side of the relay. In most models the heavy orange wire is hot all the time(key off) and goes to the battery through a fusible link. The lighter guage wires are the coil part of the relay. The 12 switched from key should be on the tan wire on the relay plug, the other wire will go to either a fan switch or the ECM depending on application. TBI models with single fan generally used only the fan switch, TPI used the ECM in most applications.

 

cool, i talked to my boss at work tonight and he said the same thing, my last question is, the fuel pump wire is tan/white i think, where is it? does it go through the fuse panel then go to the back of the car? i am going to try and find it tonight, i cut alot of wire out of the car, and some i shouldnt have, thanks for your replys.