I've been going through the harness that Pocket made for my 87 to adapt it to put it in my 88. I've moved the fuel pump wire from the C207 to the C100 as needed. I'm also trying to track down the fan wiring, but it looks like the fuse was moved the added engine bay fuse block. I'll confirm that today hopefully when I look to add another fan for my new dual fan setup. One thing that I haven't been able to wrap my head around is how the volts indicator functions.

My wiring diagram shows a brown wiring running from the alternator to Pin F8 of the C100 and then directly to the instrument cluster for the volts indicator. This is the case for both the 87 & the 88. However, when I unwrapped my harness I noticed that the wire that goes to Pin F8 is cut about 8 inches back from the connector and therefore not connected to any wires in the harness. It's been a while, but I really thought my volts indicator was working correctly when I had the engine in the 87. Anybody know what I'm missing? How could the gauge be working if nothing was connected to Pin F8?

 

That gauge is connected to the gauges fuse in the dash. It is 100% independent of the alt. it measures voltage across the system

 

Awesome. That makes my job that much easier. I noised that it was connected to the gauges fuse, but the brown wire that also went to the alternator from the instrument cluster was throwing me off. Thanks for clearing that up!

 

Thanks for this info because I was just scratching my head about the exact same thing for my '86. I dug back into the C100 and pulled out the brown wire and traced it out to the cluster wiring and was wondering where to hook it up. Nice to know that I don't need it now. Thank You!