So my fuel pump was changed by yours truly, because it wasn't whining, and after i replaced it it still wont run. Relays are good and so are the fuses. What do I do next? any input?

 

The next thing I would do is check all the connections at the fuel pump. Make sure the ground is good. Make sure the power wire is supplying correct voltage. The most common problem that causes this condition is bad ground. I believe the ground for the pump goes to the frame of the vehicle behind the gas tank. That can often build up corrosion. Make sure the surfaces are nice and clean.

 

I have the same problem new fuel pump all wired up but not installed in the tank. I just wanted to hear it run for a quick second before I bolted everything back in, so what gives? Do both grounds need to be bolted down? the one attached to the filler neck line and the wire at theback of the frame? I tried just bolting down the wire on the back of the frame and the pump is not making any priming sounds? oh damn this was supposed to be a one day project.....

 

As TH has pointed out, high on the list of things to do would be to actually verify +12V and good ground at the connector to the pump. Resistance to ground should be less than 5 ohms at the connector with the other side of the multimeter connected to a known good chassis ground. It's never good to assume that because the relay is good that the pump is the problem.

 

alright well I have not checked , I am without a voltmeter currently kinda running blind I know. I just took the day off borrowed some help from a friend and hoped to just change the pump and be done. I just posted a new thread so you could see all of the other symptoms and chain of events so far, I was still using the truck just fine but now I may shot myslef in the foot!!! Thanks in advance for any input I will just keep working , at this point I may need to undo the butt splice connectors and try something else? I just wanted to hear the pump run for a second or two. Can you tell me if the wooven metal ground wire on the smaller hose ( relief maybe?) does that ground need to be connected before the pump will run? its the one smaller hose coming out of the tank next to the larger filler hose. They both connect to the metal tubing and then the gas tank door / cap , does that wooven flat wire need to be grounded along with the other ground that is in the harness back by the rear fram near the bumper. They were both together when I unbolted but I dont think that they both need to be connected to test the pump? I have the ground connected that is wired in but not the one that goes next to the filler hose???? Thanks again!!

 

It's amazing how those one-day projects don't always finish up as quickly as they should! I am replacing the flex plate in my wife's Jimmy and was hoping to have it done on Sunday but I'm having to wait until tomorrow for a special tool.

You definitely need a voltmeter to do proper electrical testing. You can think something is working but unless you're actually reading a voltage or a resistance in a circuit you don't really know where the problem is. Even a cheap one is enough to get you through this job.

 

UPDATE: well boys still nothing. I jumped a ground to the sender harness with a full Battery and still nothing. I thought since the batery was dead from cranking it so much, charging it would help. Im going down with my fluke today to test voltage. For arguments sake let's say that i have 12 volts. Is it most likely a fuel pump problem. Id have to say no because its new. the chances are slim. But Im still at a loss here lol.

 

It is a simple device really. Given +12V and a good ground to the pump, it should run. If you verify that there is power & ground to the pump (including when it's plugged in by back probing the connections), then the pump is the only logical source of the problem.

Even new products can have faults. When they do, it is often the last thing someone thinks of.

 

New pumps can go bad. I replaced the submersible pump in my well last year. After a week the control box failed and I had to get a replacement.

Meanwhile, the Airtex fuel pump in my Blazer is still running. Apparently it's the only one...