Ok I need to know how to wire up my alternater on my 85 Iroc TPI. I recently had a tranny installed, and the installer accidently disconnected the small tan wire that comes out of the two wire plastic harness from the alternater............problem is he disconnected it somewhere near the main wiring harness near the firewall, and since my car was previously pack rat food, that area under the hood is really a mess, and even after looking for hours I couldn't find where it disconnected from. So anyways, he said it needs to be connected to a 12V battery source, so I connected it to the battery, and the next morning, the battery was COMPLETELY dead, I mean dead as a door **** dead. So at work a buddy said that wire needs to go to a SWITCHED 12v source, so I tested out some fuses under the dash and discovered the easiest one to tap into is the one with the thick red wiring plugged into the box that says "IGN" , that wire has 12v with the key on, and nothing with the key off...........just like the guy said I need to wire that tan wire too...........so I wired it up to that wired, and drove off. The alternater was charging good and I went to park the car, turned the key off............and the car keeps running like I didn't even turn the key!!! WTF???????????? Need help please. I suck at auto electronics. I had to unplug that "IGN" thick red wire from the fuse box that I had tapped the alt. wire into just to turn off the car. PLease don't tell me I'm going to have to do that every time I stop!



alright this is like the third time posted on another board becuase I REALLY need to know what to do quick! I have to go to work in like 8 hours.

 

try this site www.madelectical.com
The guys name is mark give him a call hes a real good guy,helped me alot in the past.I think all you have to do is wire in a diode to prevent the backflow of electric but he may be able to tell you an easier way.Hope it helps!
Later

 

Alright, well my car is officially uber-ghetto. I wired a switch up to that wire so that I can turn my car off with a switch.

 

Chris, there are two separate circuits that come from the ign switch - "hot in run" and "hot in run and start". When the switch is shut off, both circuits are disconnected from the battery - and from one another. The "hot in run" circuit powers stuff that does not need to be on while trying to start the engine - heater fan, windows, alternator, etc. The "hot in run and start" circuit powers stuff that must be on in order to start the engine - ECM, ign system, etc.

If the alternator is powered from the "hot in run and start" circuit instead of the "hot in run" circuit, when the ign switch is turned off, the alt continues to power the ign system, and the engine will continue to run - perpetual motion, it would seem! So, you need to disconnect the alt from its present power feed & connect it back to the "hot in run" circuit. There should be a brown (or tan) wire coming from the "FP Fan" fuse that powers the alt.

 

wire a switch to your coil high voltage to ground

 

got any pics of this mess ? why not just ahve the garage the messed it up fix it. if you paid them to work on the car and the fooled with something they shouldn't have its up to the to pay for repairs.