Trying to figure this one out.. 1991 GTA 5.7 TPI. With the key on the fuel pump is not running. Previous owner put a jumper wire with an inline fuse from the battery positive terminal to the orange power feed wire of one of the cooling fan relays. With this jumper installed the fuel pump will run with the key on and start the car, then after the car starts the inline fuse will pop but the car will continue to run. Every time you want to start the car you have to put a new fuse in and it will start, but unless you quickly remove the jumper the fuse will pop. So some assumptions, maybe correct?

-fuel pump is good and works
-fuel pump relay swapped out, no change
-oil pressure sending unit should be ok since after the car is started the with the jumper wire the fuel pump continues to run?
-putting starting fluid in the throttle body only runs the engine for a second, fuel pump does not continue to run, so ignition module should be ok?
-check engine light does not come on with key on. However I swapped the ECM and had no change. Maybe the bulb is removed? ECM must be working because the engine will run, correct?

got any ideas? I cant for the life of me understand why running 12v to the orange wire of the cooling fan relay would run the fuel pump. According to the color codes on a wiring diagram I have it is a cooling fan relay and not the fuel pump relay. Also according to the diagram there should be 12v on that orange wire anyway, fed by a fusable link...so that fusable link must be burned, any idea where it is located? Does it feed anything other than the cooling fans? Must be a reason why it would be burned and a reason why the fuse in the jumper wire will blow, has to be a short but I pulled both cooling fan relays and the same thing still happened with them removed, so I dont think the fans themselves are shorted? This is a good one!

 

Are you sure it is not the fuel pump relay?

 

swapped all of the relays, no change. If you mean am I sure the jumper wire isnt wired into the fuel pump relay, the wire colors on the jumpered relay are black with a red stripe, green, orange, and brown. Jumper from 12v is tied to the orange wire. EDIT just checked with a test light and all the orange wires for the relays are tied together, so in fact the jumper wire is tied to the orange wire to all of the relays. Same condition when I remove the two fan relays, so something is wrong on the fuel pump wiring or something. The orange wire is not shorted to ground, I can hook up the jumper wire to the orange wire and the fuse does not blow, it only blows a couple seconds after starting the engine, so something on the orange wire circuit is drawing a lot of current but only when the engine is running.

 

Fixed. Stupid things lol..I noticed while the car was running that the alternator was not working either. Checked and no 12v on the alternator post..traced that wire out and it was disconnected from the battery, and that wire also supplied power along an orange wire to the harness. There was a similar looking unused red power line still on the battery from the stereo, looks like someone took the wrong wire off. Hooked up the wire and presto, car starts, alternator works, and now the SES light works as well. Got lucky, who would of known!

 

Anytime you experience a wiring problem like this, I've found it best to undo whatever "fix" somebody else pissed together, and set things up the way they are supposed to be (and actually repair a problem if it exists)..

 

Agreed..but in this case all looked normal other than the added wire for the fix. The wire off the battery that should of been removed was running to the hatch area where there used to be an amplifier mounted. I think this car sat for years because of this issue, the removed wire was jammed down behind the battery and was not obvious to see.