I recently purchased an 85 IROC. When I started looking it over after I got it home I noticed the plug for the exciter wire and the exciter wire were missing. I ended up finding a skinny dark brown, possibly black wire that could be the exciter. Can anyone help we wire up a new exciter wire?

 

The wiring diagrams in the following link may provide the info you're looking for.

http://www.austinthirdgen.org/index.php?pid=19

JamesC

 

Just went through figuring this out for a car I purchased yesterday with a nightmare of wiring... It is my understanding that the dark brown/black wire for the excited should be wired to ign hot, but should pass through either a "dummy light" or a diode in the direction towards the alternator. This way it wont back feed the ignition and prevent shutoff. Since I couldn't find any reference to a dummy/chargeing/alternator light for my 85, I plan on using a diode.

when I got it, the voltage reference was wired to the ground lug on the starter, and the exciter wire was spliced into the pink/ignition wire for the coil, that was connected to a random red wire that disappeared into the harness but is apparently grounded through like a 50 ohm resistor or something. No idea, wiring isnt really my thing but hopefully I can get this thing sorted so it starts...

 

Just found where the correct wire leads. Mine had been cut for whatever reason and left in the corrugated shield right at the fork behind the distributor. The idiot instead wired it to ground along with the coil BAT wire (they were literally spliced together).

Anyway the wire you are looking for leads to the firewall connector on the driver side right by the brake master cylinder/ wheel well. On mine it was a brown wire as indicated on the wiring diagram. It is bundled with the large pink wire to the coil, two large red ones that I believe are for the starter (one may also lead to the voltage ref on the alternator but mine had both going to the starter I dont believe this is correct though, one should go to the alternator), and a couple other small wires. Should show 12v when the key is on.

Hope this helps!