96 F-150, fuel pumps won't engage

Have a 96 F-150, straight six, duel tanks that was in a collision about a year ago.

Did not damage the engine luckily enough, so hubby and I turned it into our little project.

Finally, because I was unemployed for awhile, we got it back together and running. We've been driving it now for about 2 months.

So, he takes it across town to get my meds and some supper. Stops at the store and can't get it to restart.

He notices that the fuel pump in the front tank won't engage. Switches over to the secondary and it won't either.

Fuel pumps and ECM are both about 2 years old. Did sit for 9 months. Fuel gauge registers gas in the tank.

Surely both pumps are not dead. When the ECM died, it still started, but it burned a tank of gas in 3 days.

I think it's the inertia cut off switch. We didn't think to replace it after the wreck, and well, it started! Started it up after getting the hood, fender and radiator out of the way just to make sure the engine was still good.

Anyone ever have this experience and was it indeed the inertia switch? Thanks in advance!

a reply to: flowerpower691

Is the fuel tank relay functioning?
There is just one that does both pumps. It is a special one for dual fuel tanks.

Inertia switch makes perfect sense if it was involved in a collision.

a reply to: butcherguy

I did forget that they tested the fuse, fusebox and relay and they are functioning.

Thank you.

Now maybe if we are right, maybe my brother in law will finally believe I know something about auto mechanics.

Hubby may try bypassing it to see if it is truly the issue, but we agreed it wouldn't be a good idea to keep it that way.

a reply to: flowerpower691

Some vehicles have as many as three small fuel pumps, and they all have electrical relays that add to the possibility of problems. Got to an auto parts store and purchase a manual to better understand the systems on your vehicle and to see if they can check it out with a hand-held diagnostic tool. Reilly's is good one.

a reply to: flowerpower691

Two things happened to me concerning this issue.

1). The cars computer was under the passenger seat, sitting in a depression lower
than the foot area, hence, water and snow run off pooled there and shorted it out
eventually. The mechanic pulled out the back seat and replaced the pump, lol,
I found the rusted out computer and found used one at wreckers. All was well.

2). Ground wire from tank to car frame was rusted out at screw to car, hand grinded
Rust free area and reattached, sweet!

Rusted out ground wire to the cars frame is not all that unusual. There are a lot of these in most vehicles, sources of a lot of issues, anyway, good luck!

a reply to: flowerpower691

find a fuel system wiring schematic online for a 1996 ford F150.

There is probably at least one fusable link in the fuel system wiring,it may have burned out.

check the fuel system grounds and make sure all the wire harnesses are still firmly plugged in.,even the harnesses plugged into the computer.

I`m not familiar with fords so I don`t know exactly where the fuel pump grounds are connected to the frame.
here are few places where fuel pumps are usually grounded, the radiator support frame, the back of the right side engine head, the frame under the vehicle.

get a volt meter or a test light and check for voltage at the pump and then work your way back from there checking voltage before and after the inertia switch.

I've had to replace the pigtail harness on my fuel pump/sending unit twice now on my 94 f150. Water gets in and shorts it out. Last time I put sylglide on the connections and no trouble since.

Turned out to be the tank switch. I had grabbed one out of the junk yard on a whim because it's not a part Ford carries for it anymore. He popped it in and it started right up.

Thank you guys!