its an 89 iroc with an aftermarket 3 pc pulley/bracket set so all you have is the alt/water/crank...well for the bracket to work the previous owner bought a new alternator which appears to be an older style case like the lt1 but i think its a cheap power master 60amp because it has two wires running to it...one is the main (one wire) the other is a tan wire with a white stripe that runs atop the drivers valve cover in the loom...what does it go to? i thought it was the fan relay but they still came on with out it hooked up...also how bad is it for the car to run a 60 or 80 amp alt? isnt the factory like 100-140 ? or something like that...thanks

 

nobody can take a second and look in the wire loom that runs across the top of the drivers valve cover? the wire exits the loom at the front of the head thats where mines cut its tan with a white stripe...thanks

 

Older alternators have 3 wires going to them: The main power wire that delivers the alternator's output to the car's electrical system and battery (single ring style terminal, big fat 10ga wire) and a 2-wire connector to run the alternator's field coil to regulate the charging. One of the wires is pretty hefty (12 ga or so) and the other is small (16 ga or so). Later alternators (like a 94-up LT-1 engine and similar vintage applications) only need one small wire to run the field coil but earlier applications like a TPI engine I beleive the alternators still had the dual wire field coil system.

You'd have to ask somebody other than me to explain exactly how the system works, I just know (or think I know) how many wire there are and roughly what they do.

 

On the old style alternators, the small white or tan wire went to the idiot light in the dash. The two heavy wires, one on the back output stud and one on the connector, eventually tie together in the system. Best advice is to find a schematic, but I am fairly certain this is correct.

 

The tan white wire should be an "ignition hot" running through the C100 connector back under the dash.
If the regulator doesn't see switched 12v from the brown and tan wire, the alternator will not charge the battery.

 

thank you...i tried using my alternator from my lt1 for the extra amps only to find out it killed my battery so i thought the alt was bad...now i know! thanks again

 

NP, Red396 and I just went through this two weeks ago with his car