2003 GMC Seirra 2500hd 6.0 loosing power and doesn't start again.

Bad relay or bad pump. Jump the pump test line to power to test the pump. If the pump comes on then the relay has burned contacts. If not then it is probably the pump OR the connector for the pump.

Lets see 6 years of constant pumping and that's BAD???

A brand new Delphi pump module is 260 bucks.

The MSD pump is 120 or so and it will not work. First it doesn't create enough pressure (40psi according to MSD, factory spec is 55-62psi MIN.) Second you would need to pull the factory pump module, then rework it so you have a working fuel gauge and fuel pick-up. It won't draw through the factory pump because of the way the pump operates.

MUCH easier to simply unbolt the bed, slide it back onto a sawhorse or two, clean off the tank, remove the pump module and replace it. While your there you will want to replace the connector harness as well. They are usually included with the new pumps. DIY should take about 4 hours if you don't have to empty out the box first. If you have to empty the box all bets are off....

This is MUCH easier than dropping the tank out the bottom unless you don't have a choice. No working around the tank to disconnect the lines or the fill pipes.

I had a friend replace a in tank one on his GMC jimmy and it died out with in a few weeks and he had to drop the tank again. I would like to avoid that whole mess and just fix it once. Then if it breaks again in 6 years then we can do it again.

After further research >> I was driving down the street to work the morning after a typical >> Colorado

And I have replaced about 100 of them and had a total of ONE come back (which was an aftermarket pump the owner supplied) The common problem is that the people don't replace the connector harness on the Blazer/Jimmy trucks. Then the pump burns up because of the faulty contacts.

Use a factory pump and you won't have a problem. Use an aftermarket pump and it becomes a crap shoot. That is why I posted the Rock Auto page. You can get the same pump that the dealer will sell you for 4-500 for a LOT less.

I would think you could return it easy enough. If not toss it on E-Bay and get your money back.

I just replaced the pump in my 98 pickup. I bought a generic pump online for $75. Dropped the tank. It was rather easier than I thought it would be. The biggest problem was getting the lines disconnected. You need a special tool, or a couple of really tiny flat blade screwdrivers to pop the internal clips. Dropping the tank took about 20 minutes and can be done on the ground with common hand tools. One strap. One bracket and you need to disconnect the gas filler hose. Once the tank is on the ground, you can break the lines free at the top of the pump as you will not be reusing the old pump. Much easier to get the old lines free of the plastic if you don't have the correct tool. Once the tank is on the ground, it's a piece of cake to replace the pump. Old one out. New one in. Aftermarket pumps require you to re-wire a new connector on, but it's color coded and only means splicing 4 wires. Note... drain the tank first. Much easier to handle that way.

Steve makes a point about removing the bed, but on mine that would have also required pulling off a fiberglass topper. I could see how it might be easier to pull the bed.

When I replaced the fuel pump I used a pin extractor on the connector to examine the crimps; the quality control standards seem to have been followed since all the crimps were done properly (no wire insulation found under the crimp section meant for just the conductor). I've done this on radios that come with a wire harness and I've found very crappy crimping.

Fortunately removing the fuel tank isn't a major job: it's just annoying having to do it twice for the same job.

Well we pulled the tank down and pulled the pump out and tried it again on the outside of the tank in a cup of water. It worked and it shot the gas out like a mad man. We are checking the fuel filter now. But I'm not sure if I need to spend the money on a new pump. It could be the filter all along.

OK a couple of days ago it died again. And I don't think its something as simple as a fuel filter. (since we already changed it again) I haven't ran thru the diagnostics myself but I was wondering what I should check for to see if the fuel pump is bad before dropping the tank.

I think that I am going to have to change the fuel pump. But I was hoping to change just the pump instead of the whole module. I want to buy just the pump and replace that. It seems like a waste of money to replace the whole module since once I drop the tank its not that much more work to take apart the pump housing and replace the pump itself. And cheaper. Can you help me find a place online or even at a parts store like Autozone, Checkers, Pepboys... but we are prepared to mail order too.

Have a happy Thanksgiving too. Thanks for your help today.

Not a surprise. That is why the original solution of replace the pump was given. The pumps develop bad brushes or bad bearings, then moving them around makes them appear to work, until they stop again.

Not possible to replace just the pump on the later units. Up until about

94 you replaced just the pump. Then they changed the pump design. After that you replace the entire module. Which gives you a new pump, fuel sock, fuel level sender and new wiring (which is frequently the cause of pump failure when the contacts fail) When you install the new module make sure you also replace the connector on the end of the vehicle harness.

Its not impossible. In fact looks rather simple to pull out the pump itself and slip a new one in. However, if spending the extra money is the best way to go I guess that is what we will have to do. I don't want to mess with this again.

What do you mean the connector? The wire harness itself or the plastic plug? What do you mean? Thanks.

No not IMPOSSIBLE IF you can buy just the pump assembly, Which you cannot. The earlier pumps don't fit in the later module housing. Now if you had a 95-96 you could use a 94 pump and make it work. That is why it becomes a not possible to do job. BTDT more than once. I've changed out probably 100 of the pump modules.

When you pull the pump module there is a connector which plugs into it on top. It carries power, ground and the level signal. The connectors tend to be a problem. What happens is the pump starts to fail and this causes it to draw more current. The higher current heats up the contacts and causes them to lose some of their tension. This has the effect of making a poor connection which increases the current draw more and makes the problem worse. I have seen more than one where the actual plastic shell was melted.

Most of the new modules come with a new connector assembly. You cut the old one off, install the new pigtail with some GOOD sealed crimped connectors and make sure they are secure. You will usually find that you have to change it to keep the warrantee valid.