MikeS

Applying 12 volts to the tan wire with white tracer (position C) on the fuel pump relay should cause the pump to run, correct?

Trickster

No, the best way to test the fuel pump is to apply 12+ volts to terminal "G" of the ALDL and negative to ground. I use a 14.4 volt battery from a cordless drill to test mine. You can also use a 12 volt battery from one.

MikeS

I tried testing by appying 12V to G. All I got was a MAF power relay click (unless I was really tired and am not remembering right). You say apply +12V to G and neg to ground. I assume you mean to ensure that the pump is grounded. I should only have to put 12V onto terminal G and not have to ground anything, right? If not, what do I ground?

The reason I asked about the tan/white wire (correction: A, not C) on the relay, is that it should be the wire supplying power to the pump when the relay is switched on. That's what my wiring diagrams tell me anyways. Green/white (wire C) is the +12V control for the relay. Applying 12V here trips the relay, and should sent 12V to the pump via the tan/white wire. Am I reading the diagrams wrong?

Isn't it just like a fuel pump to die when I've got 500 miles to drive by morning...

Trickster

Hello Mike,
when I said negative to ground, I meant a good ground on the car frame or terminal "A" of the ALDL. Just curious, but what problems are you having that leads you to believe the fuel pump is bad?

Vader

Yes, you can apply +12V directly to the tan/white wire. That will completely bypass the relay NC contacts, ALDL wiring, and bulkhead connector at the firewall. Naturally, the pump shoudl already be grounded. If the pump doesn't run, the ground would be a good item to check, along with all the connections at the tank.

MikeS

Car wouldn't start yesterday. Actually, it ran for a few seconds once, then not anymore. Realized that I wasn't hearing the pump prime when I turned the key on.....

So, I checked my relays and fuses. All seem ok. Released all the pressure from the TPI fuel rails at the schraeder valve. Turn the key on, and still don't get a pump prime. MAF and fuel pump relays (assuming I've identified them correctly....using Vader's labeled pic and a wiring diagram) click (granted that doesn't mean contact is made).

So, all seems to lead me to the pump. Thus far, I have assumed that the ground to the pump is still good. Right now, the car is up on jackstands ready to start the job. I'm pulling the electrical connector running to the top of the tank. I'm assuming that of the three wires there, one is 12V to the pump, one is ground, and the other is signal from the fuel level sender. I'll try powering the pump directly from there in a last desperate attempt to say the pump is still ok.

Thanks both for the input!

MikeS

Well, unfortunately, that was it. Took almost all day yesterday (while I was supposed to be at work 500 miles away), but got the new pump installed. Runs great now, although it seems like I've got to reset my idle speed....