[Ford Assassin]

Originally Posted by hatzie

Bypassing the relay is a bad idea.
It's a more reliable setup to use the 1987-91 fuel pump relay as it was originally setup by GM.

Why?
The relay isolates the PCM from the fuel pump power circuit. This keeps fuel pump wiring problems and fuel pump problems from smoking the fuel pump driver transistor in your PCM. When you let out the magic smoke you can't put it back.




The original TBI ECM has two connectors.
A & B.
The individual terminals in each ECM connector are numbered.

The fuel pump relay connector terminals are lettered A-F. As you can see in the above wiring diagram.

Splice the LS fuel pump power wire to the TBI fuel pump power wire... according to the diagram above it's a Green with White stripe wire from the old ECM Connector A on Terminal position 1 to the relay plug terminal position D.

I guess I am confused. I have a separate relay for the fuel pump in my stand alone harness. Why would I want to run through another relay? Not meaning any insult, just asking for clarification.