No power to fuel pump

[dlundblad]

The fuel pump on my Blazer isn’t getting power. I can hear the relay turn on in the glovebox and can confirm it’s not the pump since I have a spare that I also tried. It will run on starting fluid btw.

Sadly, I just filled the tank so before I go messing with this, is there anything else I should be looking for? I’m guessing it’s wire related.

 

[spasm3]

The relay could be bad even if it clicks. Time to get out the multimeter and look for power.

 

[wag123]

During that era, GM had problems with the electrical connector & wiring harness going to the fuel pump on top of the gas tank. This common problem is documented all over the Internet. In fact, I'm pretty sure that they had a recall for this, but I don't know what specific years and models were affected. This problem is so common that some new fuel pump modules come with a new connector and wiring harness.

 

[Trav]

The fuel pump on my Blazer isn’t getting power. I can hear the relay turn on in the glovebox and can confirm it’s not the pump since I have a spare that I also tried. It will run on starting fluid btw.

Sadly, I just filled the tank so before I go messing with this, is there anything else I should be looking for? I’m guessing it’s wire related.

Check the fuses, relay and engine oil pressure switch. You can jump the pressure switch to test if you are getting power to the fuel pump harness.
Hope this helps..

 

[WyrTwister]

Yep , I would replace the relay , first . They are usually inexpensive . If that does not fix it , time to get underneath with a multi-meter .

 

[Kestas]

I've fixed many similar problems by taking the relay apart and filing the burn off the contacts... a no-cost fix.

 

[dlundblad]

The pigtail for the pump is the updated version. 1x4 rather than the 2x2.

I also exchanged relays to see if that was the issue.

Thanks for the other advice.

 

[zzyzzx]

Yep , I would replace the relay , first . They are usually inexpensive . If that does not fix it , time to get underneath with a multi-meter .

Test before replacing parts!!! Relays are easily tested.

 

[thastinger]

Have you looked at the crash activated fuel pump shutoff?

 

[dlundblad]

Check the fuses, relay and engine oil pressure switch. You can jump the pressure switch to test if you are getting power to the fuel pump harness.
Hope this helps..
View attachment 26572

How would you bypass the oil pressure switch? The harness side is a 2 prong female weatherpack connector.

 

[dlundblad]

Have you looked at the crash activated fuel pump shutoff?

I’m not sure where this one is located or even if it has one.

 

[wag123]

I’m not sure where this one is located or even if it has one.

I don't think that your Blazer has one. All Ford products do.

 

[Trav]

How would you bypass the oil pressure switch? The harness side is a 2 prong female weatherpack connector.

Remove the connector and use a jumper wire between the two terminals which is essentially what this type of switch does in normal operation as in the illustration, pressure closes C&D.

 

[dlundblad]

It was a bad ground to the pump. Thanks guys.

 

[clinebarger]

The oil pressure switch is a fail-safe in the event the relay or ECM failed. You'd just have long crank times ('til oil pressure built & closed the switch)

 

[WyrTwister]

It was a bad ground to the pump. Thanks guys.

Congrats !