major power drain within a 24 hour period of my truck sitting. My fuel pumps are staying on. I have replaced both relays,still not working. Think i have a short somewhere. does anyone know of a way i can bypass the relays and put in a toggle switch to turn on and off pumps.
thanks

 

The mess of an '88 F150 I bought 3 weeks ago, PO ran a wire that he messed around a 15amp fuse in the fuse box under the dash, stuck the fuse back in it's slot and now everytime you turn the key to ON, the fuel pump starts pumping, only time it does stop is when you turn the key off.

 

You could by pass the relays, but that is not a good solution to this problem. The fuel pump relay gets power from the EEC relay. It is the PCM itself that tells the fuel pump relay to turn on.

Did this problem just appear or did you inherent someone's electrical work?

 

I bought the truck like it is. I have no idea how long its been like that.

Theres a bunch of add on wires under the truck with a bunch of cut and spliced wires together with marrets and electrical tape, it's a mess under there!

Key on, lights off, left turn signal flashed kinda slow (right one is also slow), and the 5 cab roof lights and dash cluster light flashs along with the left flasher. I took a test drive today after rebuilding the rear end, and I noticed when I had my left turn signal on, the engine light and buzzer was flashing and buzzing with the signal to. lol Only happened on one turn, but still WTF? lol


When I pull out my light ****, all lights work fine, but the brake lights are always on, when you apply brakes, makes almost no difference! And when lights are on, left turn signal doesn't work, just comes on. Doesn't flash.


Got some nice electricals in my truck eh?

I followed a black add on wire comming from the pack of taped marrets that was shoved over the rear gas tank, and it was grounded to the fender where the cab plug ins ground to the fender. When I unscrewed that screw, and the wire lost contact, the 5 cab lights came on when nothing else was on, I do think the key was on, but nothing else.



I'm not even gonna bother more than I have to with all that BS!

I kepted a complete wiring harness, cab, rear harness, everything that was on my 1990 short box F150 parts truck.

I'll re-wire this truck!

 

Good luck, sounds like quite a mess.

 

Relays? There is only 1 fuel pump relay AFAIK.

 

It's to bad, trucks in really good shape! Box is rusted, but cab and front clip is mint!

Can't imagine what's this trucks been through.... has an overload spring pack in the back, making 10 leaf springs per size plus has a gooseneck hitch in the bed, and by the size of the gooseneck trailer I saw when I went to pick up the truck and parts that came with it, he wasn't hauling light loads....

No wonder the rear end was all messed up and loose on it!


Heres a pic of it.



Interior's abuit dirty, but not abused or damaged so it'll just need a good cleaning!

 

Relays as in the EEC relay feeds power to the Fuel pump relay. The PCM controls the return side of the fuel pump relay to turn it off and on. I used plural because one feeds power to the other.

 

my fuel pump relay sticks... gets annoying when its pouring down the damn rain and its like 40*F outside...

i replaced it.. still sticks.. so i said **** it... when it sticks i pop the hood and flip the **** lol

no it doesnt stick all the time but it does occasionally