Recurring fuel pump problem

A few years ago, I had 3 fuel pumps replaced on my 1999 Pontiac Montana in the space of a year. By the 3rd time, the mechanic found that there was a problem with wiring (he said that it wasn't grounded and that it kept burning out the fuel pump). So he rigged it so it wouldn't happen again. And it didn't...until last year a couple months after I had the AC replaced. I put in a new fuel pump (well, had it put in) last September by a friend of a friend (yeah, I know) and I told him about the problem and he said he checked it and fixed it. Anyway, in June of this year, I had another fuel pump problem and I took it to a mechanic this time, and he said he fixed the wiring.
Then, a few days ago, again, my van dies. It will start again after a few tries and pumping the gas. I took it in, he said it wasn't the fuel pump this time. He wasn't sure the problem, but fixed a few things he thought might be it. I picked it up on Saturday, and it died again. (He couldn't get it to die). Again yesterday. And once today on the way back to the shop. This time he said if it's the fuel pump I won't have to pay, but if it is the fuel pump, OBviously the root of the problem hasn't been fixed yet.
Any ideas? I tried to explain the electrical problem thing, but I really don't know what I'm talking about, I'm just repeating what I remember from 4 years ago. Anyone had this same problem? The van computer doesn't show any problems.

Yea, I have an idea. You should have read this forum sooner:nono:

There are several threads here about the bulkhead connector just behind the driver's seat. This is a cable connecter that carries the wires for the fuel pump (hot & ground), the evap purge cansister, the fuel gauge and the intank fuel pressure sensor.

The van collects water (spilled pop, wet feet, whatever) and holds it under the carpet. This dampness rots out the connector where all those wires pass though.

You can check that this is the problem by jacking the van up a bit, and getting your head under the van just behind the driver's seat. Look up near the edge of the van and you will see the multipin connector plugged in up there. Unplug it and have a look at the pins inside to check for corrosion. There are two connectors close by. The one farther back is for the tail lights and optional air compressor, you want the one more forward. They are about 3 feet apart. Look right behind the driver's seat.

Do this when the van is parked and you don't have to move it for a while cause if that connecter is as bad as mine was, it won't be running until you fix it.

There is no special ground for the fuel pump by the way, not that would cause the motor to stop running or burn up. The only power wires to the pump are the two that run through that connector.

If your check engine light comes on with an Evap code all the time, this is also the first place to look.

Good luck

it is called the pass-thru connector and it also gets moisture from the bottom side rain, snow. as the weather seal that g.m. used to seal it does not seal it. most of the time when you pull it apart it is green inside and the pins are rotten.g.m dealer will sell you one .the top pass-thru part of the connector is $180.00 the bottom part is $55.00 they come with all the wires colored grey . you will have to carefully figure out which wire goes to which wire and cut and splice and heat shrink.sometimes you can spray electrical cleaner in both ends and be careful not to move the pins much as they will break off.a neighbor of mine has a venture that had this problem rather than buy the pass-thru box he just added more wires of the same color and drilled a hole thru the floor and spliced them.i don't know what engineer came up with this design but he didn't think it through to much.one other thing these fuelpumps are made in mexico as was the factory one. they are made mostly of plastic i don't see how they last as long as they do.

Holy Cow, I posted a thread a few down from this one earlier this month about the fuel pump. Replaced mine with a Carter's from Napa, worked for a day, got another one worked for about a month. Gave up and had it towed to dealer. They called today and said it needed the wiring fixed as described in this thread. Banging my head against the wall trying to figure out how I could have botched the replacing of a fuel pump, now I wonder if it even needed one....

when you go back to the dealer tell them that g.m. should fix this connector free of charge or at least half of it. as the seal that is supposed to keep moisture out does not keep it out.piss poor design. mine did this and it ended up costing me around $100.00 with me doing it myself. i won't ever buy a g.m. product again.

Just picked it up from the dealer, I'm nervous.

My receipt says $120.00 labor and $8.00 Misc (Extra Item) with tax $128.48.

Misc (Extra Item)???? What did they do, just spray it down with some type of cleaner???

the dealer could have tried to clean it with electrical cleaner. sometimes if its not too bad corroded it works. but if the pins are corroded real bad they will break off.sounds like it took the machanic hour and half at 80 dollars an hour and they put a new seal in it.

I wouldn't even fool with that connector. Splice around it. I researched for a while and found out the correct part numbers to replace just the metal pins inside the connector. Once I had the numbers, I ordered them from GMparts. Saved a ton of money that way, only spent about $20 bucks for the pins. Problem was, the wires themselves had corroded to nothing as well as the pins. I don't know how it was working at all.

I got into the connector in the begining to fix the evap code on the van and ended up busting the fuel pump when I unplugged the connector to check it.

In the end, I spliced new wires from inside the van to a foot back under the van. Left the old connector in place just to fill the hole in th floor but not using it at all for power.

That was the best fix in my opinion; ignore the connector and just splice around it.
John