Brockrags

I have a 97 f150 with the 4.2 v6. I was driving over a bridge and it just killed on me. No power to the fuel pump. Pump fuse was still good. So I replaced the pump. Still no power to pump. Then I realized the position 24 PCM 30 amp fuse was blown. Replaced it and truck ran fine for about ten minutes and died. Popped hood and fuse was blown again. I put another fuse in and as soon as I turn key on. Dome light goes dim for a second and the fuse blows. I've looked for a short. But can't find one. I read in a few other threads that the harness can touch the exhaust on passenger side and melt causing a short. Any advice would be much appreciated.

bobkyle2

GEM module is my guess...

Teri

OMG. I am having the exact same problem with my 97 Ford F150. I have replaced everything from the ignition coil to the PCM (the computer "brain" of the truck) The guy that has been working on it is baffled. I replace the PCM fuse and just like yours it blows as soon as I try to crank it..someone please help!!

OneForVendetta

Similar issue here... But with the fuel pump fuse. I was out on business for a week, came back, and my truck will crank, but won't start. I noticed the 20a fuse for the fuel pump in position 10 was popped, so I first replaced the fuel filter and relay.. the problem persists. I replaced the fuel pump yesterday, but it keeps popping the fuse and dying after just seconds...

pickupsrule

I would check all ground wires first.
I think the only way you will find the short (yes there has to be one) is to get a multi tester and check the resistance at every single wire coming from the fuse location (from wiring diagram). You can also do the wiggle test (which is expensive) where you wiggle each wire coming from the fuse location until the fuse blows. You can use a lamp bulb too which will dim in and out, but the multi tester is best and you can get a real good one for about $25.00 or so at Lowes and it can be used for your truck, house, electronics, etc. I never thought I would use a multi meter as much as I use mine. If you buy one, make sure it uses standard batteries and not special batteries. I fell for that one and threw one away because the batteries cost more than the stupid meter.
It's the only way you can find the short and that is what a shop would use. Honestly, it could be anything, and most likely will be some stupid thing on one has thought of.
Blowing 30 amp fuses is not a good thing at all, and is probably melting down the wiring insulation each time it shorts out.

OneForVendetta

Haha Thank you, sir! You are likely correct... I just didn't want to come to the reality of the situation.

OneForVendetta

Good news, I found out my problem. My truck is a 2001 F150 7700 Bi-Fuel CNG / Gasoline 4x4, and they actually route the circuit for the CNG tank valve through the Gasoline Fuel Pump fuse on the fuse board. When the tank valve goes bad, it blows the fuse, making it so the truck WILL NOT run on GAS or CNG... Too bad it cost me a fuel pump before I found out it was a $250.00 tank valve... I want to get the word out!

pickupsrule

Great! As for the fuel pump, that will eliminate you having to worry about the fuel pump going bad. A new fuel pump is always a good thing because it is the heart of the fuel system and when it goes, your truck gets the hook. I'd say you came out pretty good overall as far as cost goes. It could have been a lot worse. If you haven't done so, you should go to this site and check your truck for open recalls.
http://www.flmowner.com/servlet/Cont...FRFj7Aod2h2ZXw

Ale

I have had the same problem. if you disconnect the bad valve/tank and replace the fuse the truck will run -that tank. Im having ahard time finding a replacement , the local ford dealership quoted me 1000.00 a piece. can anybody help? Thanks

robertcordle

I also have a 97 F150 blowing #24 fuse. I found the sensor on the passenger side the wires were grounding out. I moved the wires and the fuse stopped blowing.