Customer stated that he has installed two fuel pump assemblies within a few days and fuel pump fuse continues to blow.
Removed the fuel pump fuse and relay and replaced with fused jumper wires that have manual reset circuit breakers install. This allowed testing without having to constantly having to cycle the key for fuel pump operation.
Circuit breaker would trip instantly. Time to start isolating. First raise vehicle and disconnect fuel pump harness at floor pass thru connector located behind driver’s seat.
Short still present. Located and disconnected harness junction block at right front kick panel.
Short was now gone. Short has to be under carpet in passenger compartment. No signs of body damage and it did not appear that the seats had been out. So where to start? I decided to look at the connector that passes thru the floor behind the driver’s seat. Lifted the carpet and saw a metal shield over the connector and some gummed up wiring.
Knew that I was close so I drilled out the rivets that were holding the plate down. Lifted the plate and there was the short.
Removed pass thru connector, removed and replaced burnt terminals and wiring. Cleaned remaining terminals and installed dielectric grease as there was also signs of water intrusion. Reassembled connector to floor board with bolts and nuts and reassembled vehicle. Actual repair time took about five hours from start to finish. It can be done in less than two with this info.
I would recommend checking power and ground to the fuel pump when the condition is present. The only other thing to do would be to inspect the harness connector under the vehicle and see if it is water damaged//corroded.
Trevor, Thank you for using this site as I have intended it to be used. Any post that I do is not intended to be a silver bullet but rather a statistically good starting point for doing some testing. I am sure others will benefit from knowing there is another place to inspect for damage.
Sparky, Your info was a great place to start my diagnosis but did not solve my problem. I ended up finding my wiring issues on the passenger side floor by the kick panel. I had to repair 8 wires because they were shorting out resulting in the fuel pump fuse blowing all the time along with the speedometer malfunctioning and giving erratic readings. I am not 100% positive what caused this but I just wanted to let others know that there is another place they can inspect as well. Keep up the great work!
I had all these parts so didn’t cost me anything. I changed the fuel pump relay and computer still nothing. We were driving and it just died. Finally I found the connector. Now let me ask you, is that the best spot for that connector? I noticed my connector didn’t even have the little rubber gasket. Nice engineering guys. Wish I would of read this before I did all that work!
Sparky, You are a super hero. I am a few hundred bucks better off since I googled and found your 99 Montana post. You are a stud. The timing was right, I was not working and could be at my mechanics when he looked at my van. A fuel pump was purchased and ready to go until I told him about your post and diagnosis. He looked where I told him to look from your photo. Corrosion and a few disintegrated pins. Saturday is a bad day to find dealer parts for that plug in junction, so we both agreed to cut both ends drill a hole through the plastic junction box and straight wire it for a quick and very inexpensive fix. He spliced, taped, siliconed and voila. It took care of a year long code light that we thought might be the gas cap and amazingly the fuel pump got its much needed juice. My mechanic now has your blog sight. I told him you were a must. Thanks again Sparky. Chris G.