Silly question...

[CROW T. ROBOT]

But when I need to "ground out" the terminal on the diagnostic port for the fuel pumps, what exactly does that mean? Am I just taking my test light, hooking up the aligator clip to the negative side of the battery and then sticking the pin in the terminal?

Thought I'd do some testing before ripping the truck apart.

 

[Spott]

No, it's even simpler than that. What you need to do is take a wire, hook one end to the terminal in question, and hook the other end to ground. Ground can be a clean spot on the body or the engine, or it can be the negative battery terminal.

The ideal wire for this application would be 16ga, green or black insulation, with a spade terminal crimped on one end, and an alligator clip on the other end. However, almost any wire that's long enough, with stripped ends, will do.

Spott

 

[CROW T. ROBOT]

Excellent, thanks Spott.

 

[Psychopete]

search on google images for fuel pump test ecc-iv to get a diagram of which lead it is. Wiring diagrams show that the ground wire from the computer to the fuel pump relay has a splice to the diagnostic connector. Grounding that essentially overrides the computer control for the fuel pump circuit.