OK, I have this C500 connector drawing:



Noitice anyting missing? How about wires for the temp gauge, oil pressure gauge and oil pressure to fuel pump relay wires, Spedo wires, and I am sure there must be others. There is only one other connector to the engine and it goes only to the computer, and I know the computer does not read the tach pulses or the spedo pulses or have anyting to do with the temp gauge or oil pressure readings. So where are those wires located? Larry

try this
http://www.chalnet.net/Fier...0pinout/c203c500.pdf

also

[This message has been edited by Pilot Abileen (edited 08-18-2013).]

The engine is connected to the chassis electrical system not only at the C-500, but also at the C-203, a white/black plug that lives under the ECM. The ECM also has three plug-ins. The C-203 harness is part of the loom that runs thru the firewall for the ECM and ALDL plug.

Good info also at the sinister performance website.

Really want to thank you guys, I was very mistaken about how all this works, but it is becoming clearer now. Thanks again. Larry