Fuel Pump Fuze Blowing Help!

Discussion in 'SN95 4.6L Mustang Tech' started by jacklane322, Aug 10, 2014.

  1. I am new to stangnet and have an issue. I was driving fhe other day and my car died. It would crank but not start. I check the inertia switch in the trunk but wasnt tripped. Found a fuel pump fuze blown. Swap the fuze and tfied to start the car and it blew again. Towed it home and unplugged the fuel pump to see if tbat was blowing it. Turned the key on where the fuel pump should prime and the fuze did not blow but when I tried to start the car it blew. Im at a loss. Is it the ccrm because the fuel pumpnrelay is integrated or a bad pump or grounded wire! I check voltage and am getting .8 volts when the ignition is on and stays there when cranked. Im confuzed, I can do a 32v swap but cant figure this out. Can anyone help me!!? Or has anyone had this issue? The vehicle is a 97 gt
  2. @Noobz347 can you move this to the appropriate forum?
  3. How do I do that?
  4. Thread moved to SN95 section.

    No worries. I put it into the correct forum. You'll find the best responses for questions about your model year in here.
    jacklane322 likes this.
  5. Sounds like to me you have a bad ground that is causing your blown fuses. Recheck all the grounds, chasis, engine and batttery and tank.
  6. On many 98 and older Mustangs there is an error in the owner's manual. The fuel pump and PCM fuse are backwards. So you may be blowing the PCM fuse instead. One way to find out is to attempt to connect an ODB2 scanner. If the scanner fails to communicate it might indicate the PCM isn't being powered.

    For the 96-98 model year Mustangs one of the more common reasons for blowing a PCM fuse is an over load in the O2 heater circuit. One of the more common reasons is O2 pigtails touching hot exhaust after an exhaust upgrade. If not able to locate an obvious wiring harness damage with a visual inspection, consider disconnecting all (4) O2 sensors and see if this stops the fuse from blowing.
  7. Yeah thats what I would have thought but I hard wired a grojnd and hard wired a 12v constang from the ccrm and fuel pump and the pump still didnt make a sound
  8. And i heard that the fuzes were labeled wrong but i would have thought if it were the pcm them the car wouldnt crank or anything. im at a loss right now and dont want to just start throwing parts at it. i think im going to check the o2 pigtails and if i dont have any results im going with a fuel pump.
  9. So i unplugged the o2 sensors and fuze still popped. them i unplugged the ccrm and fuze did not pop then i plugged the ccrm back in nd unplugged the fuel pump and the fuze popped again. so im guessing its the ccrm or the inertia switch. electrical is not my strong suit so any help would be greatly appriciated!
  10. I think its the ccrm or the wiring from theu ccrm to the harness clip by the computer in the passenger kick panel. im going to swap this out and see if that solved the problem
  11. Ive seen plugs/harnesses at the fuel hat with issues as well.
    jacklane322 likes this.
  12. New update put in a new ccrm and no luck then I tested it. Got all the way back to the inertia switch and still didnt blow so I plugged the inertia switch back in and unpkugged the fuel pump. The fuse blew so I knew it had to be a short between the inertia switch and the harness plug by the tank. Cound that when I bolted my zex wet kit in I pinched the wires and the grommet in the trunk floor. The fuel pump power (brown/pink) wire was grounded. I appriciate all the input and comments and im definately a fan of stangnet!
  13. Now we are getting somewhere. That is why I firmly believe that if someone made a repair or upgrade, then a problem arises and persists, we need to know about what you did up to the point the problem started or we are just throwing guesses out there based on knowledge and experience. Did this issue arise before you did this install of the ZEX wet kit?
    #13 stangr5oh, Aug 13, 2014
    Last edited: Aug 13, 2014
  14. No the kit has been installed for about a year but i must have hit a bump just right and grounded the wire.