Ok....first, the connectors. Connector C502 is in the engine compartment along the firewall here...

Next is the gauge cluster wiring....you want the C3 connector on the left side, terminal 7

This diagram gives you the resistance values for a full tank and empty tank on terminal 7 on the pink wire.

The routing is pretty straight forward....

And the test procedure....

So the key wire is the pink wire that goes from terminal 7 at the gauges to the C502 connector at the rear.
Hopefully this helps.
[This message has been edited by IMSA GT (edited 12-30-2007).]