ls1 swap question fuel tanks

[Desert1957]

Originally Posted by glock35ipsc

Test lead? Does that go to something other than the fuel pump relay?

Here is a copy from the 87 Factory Wiring Manual , It shows the wire you are talking about (circuit 490) is a switching wire back to the relay and then conects to the "ECM" (engine computer).

I will include the wiring to the "Tank Switching Valve" which show the circuit back to the sender/Fuel Pump

I know these diagrams can be hard to follow , take your time and follow the circuit number.

Hope this helps you out...

Desert