Fuel Pump Relay Fuse Keeps Blowing!!!!

VistaGT · 12-06-2010, 08:38 PM

Hey all,

I need some help. I've installed my blower (Roush M90) and upon trying an initial startup the car cranks but won't start. I checked the fuse and low and behold the fuel pump relay fuse is busted. I put in a new fuse, go to start it, same deal. Obviously the car keeps blowing that fuse

What am I doing wrong here?

Any ideas????

Thanks!

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siggyfreud · 12-06-2010, 09:42 PM

Maybe a stupid question but are you sure the right size fuse is going in? Was there any electrical work done to the fuel pump/car at the time of install?

VistaGT · 12-07-2010, 06:29 AM

yes. 15amp. I did some wiring on the car (I thibk roush piggybacks the IC pump to the fuel pump) maybe I didn't wire it perfectly and there's a short? The IC pump works fine

VistaGT · 12-07-2010, 06:13 PM

No one has any ideas/input? Rechecked the fuel pressure regulator plug, still blowing the fuse. Could a bad fuel pump blow the fuel pump relay fuse???

siggyfreud · 12-07-2010, 06:43 PM

Did you check your wiring? I find it suspect you did some wiring in regards to the fuel pump and suddenly it's blowing a fuse.

charliebrown266 · 12-07-2010, 08:17 PM

did you by chance use the wrong harness plug into the pressure reg? its the same has the one on the Tbody

stealth_GT · 12-07-2010, 08:39 PM

Ditto on the wiring, I'd double check and go through the wiring plugs/harnesses once around again. If you're fuse is blowing up, it could mean a "dead short" in your fuel pump relay wiring somewhere. I doubt that though, unless you really whacked out on your wiring somehow..

VistaGT · 12-08-2010, 08:05 AM

I don't think I swapped it with the TB wiring. Both the TB wires have the red tabs don't they? If its this fuse consistently blowing I can assume it has to be an issue with a wire from the fuel pressure regulator plug, correct? At this point I guess its a short so tonight ill take apart the entire engine wiring harness and trace those wires to check for cuts in the insulation or bends/pinching. Of this wire did short that section must be replaced right?

wayne613 · 12-08-2010, 09:20 AM

Quote:

Originally Posted by VistaGT

I don't think I swapped it with the TB wiring. Both the TB wires have the red tabs don't they? If its this fuse consistently blowing I can assume it has to be an issue with a wire from the fuel pressure regulator plug, correct? At this point I guess its a short so tonight ill take apart the entire engine wiring harness and trace those wires to check for cuts in the insulation or bends/pinching. Of this wire did short that section must be replaced right?

If it's actually shorting due to bare wire, yeah. You could just cut it where it's bare (if that is indeed the issue), use heat-shrink tubing to insulate it again, solder back together with a portable soldering iron. Still be a bit thin though, depending on how warm things get where it is and the actual current draw on it.

So long as the fuse is blowing right away there shouldn't be an further Chernobyl action (melted wire)to need to replace the whole line.

stealth_GT · 12-08-2010, 09:47 AM

shouldn't there be a current limiting resistor somewhere in the fuel pump relay circuitry somewhere? if it's blowing fuses, would that mean that the short to ground is after the source of voltage and not before (fuel relay plug), or am I seeing things incorrectly??