Yellow_stang

I really need help guys my car will not start and it keeps blowing my 20amp maxi fuse its number 25 in the fuse box what can cause this fuse to blow do you guys think my tune will cause this since i got it tuned about 3 months ago and it never did this before it also backfires when i try to start it and then it blows the fuse as soon as a i open the key switch to try to start it... any suggestions are welcome guys thanks...

my car is a 98 Mustang GT 5 speed with the following mods C.A.I, 75mm throttle body, plenum off road x-pipe with magnaflow mufflers, 4.10's and 100 shot

WhiteFoxGT

Im checking my wiring diagram and its giving me no #s for the fuses under the hood (I assume this is where the fuse you keep blowing is.) There are 2 20A maxi fuses....one for the PCM and one for the Fuel Pump. I'd be willing to bet the Fuel Pump fuse is the one your popping. To double check, go out to the car (with #25 fuse blown/removed) and turn the key to the run position. If your CHECK ENGINE light is on, then you are popping the fuel pump fuse. IF you have the CEL is off then you are popping the PCM fuse. If its the pump then you most likely have a dead pump... Its probably locked up and drawing too much current. Check this for me and get back to me I'll be able to help you more from there

uberstang1

I had the same issue with the fuel pump fuse, it turns out the fuel pump relay (located on the harness near the PCM in the passenger kick panel) was bad allowing to much current draw. Replace the relay and it fixed the problem.

Yellow_stang

i removed #25 fuse and open the ignition key and it would only flash my theft light, and i couldn't hear the fuel pump turn on, but no CEL came on, i also replaced my PCM modrule already and it still does the same thing...

WhiteFoxGT

So wait, you replaced the PCM already??

If you have no CEL with the key on, then thats your first problem. The PCM fuse is popping for some reason. Your goin to have to get a wiring diagram and start tracing wires looking for damage. Or the PCM itself is shorted... Im not guaranteeing anything, but thats what your problem sounds like to me.

Yellow_stang

right now i started the car and it's idleing just fine but when i give it gas to like rev it, it will want to die and it starts studering but if i slowly pick up the rpms theres no problem at all i tried looking for the fuel pump relay near the pcm but i didnt see no relay's near there... i wonder where is it located exactly...

uberstang1

Its in the harness inside the passenger side kick panel. I forget what color the wires are for it, but just look in the haynes manual then follow them to the relay.

gsx3650

alright guys im having the same problem, but its when im driving, fuse blows and car dies, its maxi 12 (fuel pump) but its also maxi 13. Then my altinator goes. i have replaced 2 altinators and the last one i replaces blew maxi 13 and killed the altinator, i have a new altinator now but don't want to risk being stuck on the road again...any ideas? would a faulty fuel pump be blowing fuses AND altinators?, im puzzled.

Vovovovan

Same problem here. Did anyone solve it yet? My car died for no reason, I right away thought of the fuel pump, replaced it but it still doesn't start. Then I found a blown eec fuse. Took my ccrm apart, replaced the fuel relay and was holing that it'll start, and it did nut only for a second, then blew the fuse again. My thread doesn't get any attention so I was looking if anyone resolved the problem

gsx3650

yea buddy, had the problem and fixed it. lucky for you it was me that paid the 1200 worth of ford machanics thinking they know what the hell it is they are talking about. its ur o2 sensor. or o2 sensor heater. its either rotted and shorting out, or broken. But thats the problem. PERIOD. no if buts or maybe's about it. o2 sensor. u can thank me later.