Quote Originally Posted by Zukikev View Post
Yeah sorry I mean C and N and they are both Ignition 3 voltage. I found an ignition 3 in my 1998 C100 (D8)? I was mostly curious what it actually is.

My fuel gauge doesn't work either. This should be dead simple... No?
C1 pin 9 is a purple wire says fuel gauge.
C3 pin 13 is purple/white says fuel level module.
Connect them. Nothing. Did I miss a ground? Miss the boat entirely?
Diagram below.

TCC brake switch. Purple wire, circuit 420. It is spliced off to the cruise control module, so I took it from there. That should work right? I haven't been able to throw a test light on it to verify that it shows 12v until the brake pedal is pressed. The Alldata diagram is below for reference.

Also, in my c100 from the GenIII pcm, pin J that is suppsed to be BLK/WHT is actually Blue. I haven't asked Nelson about this yet, just wondering if anyone knows.
Your fuel gauge, there should be a connector some where around the fire wall on the drivers side with fuel sending unit wires. Unplug it there and ohm it out, from the looks of the diagram your on the right track.
For TCC that should work.