Hopefully somebody has some insight on this.
Ive got no power at the fuel pump harness. If I run a wire to turn the pumps on the car will start and run fine.
This happened out of nowhere the car was running fine.
The EEC relay is working fine. You can hear it click when you turn the key, and everything else running off that is fine. The signal wire to the fuel pump relay under the seat isnt getting any voltage.
The "always hot" wire is and again if I jump this wire over with a paper clip the car runs fine.

Where else would I be looking? Where does the fuel pump relay get its signal from?

 

What year car?

The pump relay normally gets a signal from the EEC (Computer). I would think it would ground the low amperage side of the relay. That is how most Computers control a relay.

 

Fuel pump inertia switch?

 

89

And the inertia switch is what it was. Is that something that people commonly delete?

It killed my pumps right at a hard launch at the track.

 

Good catch. I forgot about that thing. I would bypass it.

 

Fuel Pump Intertia Switches are not that expensive, (can be found in junk yard vehicles of the same year), and save you from nasty hospital recovery issues down the road when a drunk plows into your vehicle and the fuel pump stays on (because you bypassed the switch).

Skip a couple of movies with your friends and just buy a proper switch for the system.

Tom V.

I had a friend (burned up in a fire at his home) because he was adding an electric fuel pump to his car, there was a spark, and he was burned over 80% of his body by the fire. May he rest in peace.

 

Or, you could make it like a lot of GM vehicles, and add a switch that won't let the pump run when it has no oil pressure.... I maintain a fleet of taxis, (used to be all Crown Vic/Grand Marquis), and every few weeks, a taxi would get towed in, or a driver will call, with a dead vehicle.... reset, or have them reset, the inertia switch and good to go again, usually happened after going over a big bump or dip, or hitting a speed bump a little too fast, once even when somebody slapped the right rear quarter panel...

 

Check fuel pump fuse and oem relay for ingnition, inertia switch.

 

This help me out a lot check this link

http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/fuel-pump-relay-tests-1

 

Wow, I answered this question yesterday with a few paragraphs, what happened???
Short answer: On most GM and many Chrysler vehicles, the ECM primes the fuel pump for a few seconds.

 

It showed up when I posted it, then I went later to look at a reply, and my post was gone.
You could accomplish the same thing with a "prime button", which could also act as a theft prevention device too, no prime, no start, no run.

 

No big deal Ken, just thought it was curious... I am always either on the shop computer or the home computer, both Bright House Network, about 1.3 miles apart.

 

I was reading this thread tonight and do not have a clue what happened to the thread.

Tom V.