Some one asked this question but the thread went away to fuses and bare wires.

96 blazer , 157K miles, not getting fuel. checked the schrader valve and no fuel. Took it to mechanic friend and when they got around to work on it the truck started up. They said it might have been stuck relay. I drove it to the front of his lot. When I tried to pick it up later it wouldn't start. I was told ththat one of two blocks(1 inch square and 1 1/2 inch high) hanging on the firewall would be the Relay. I went to get a new one and the parts place had a relay with same pin configuration but half the size and no way to lock into the block. Hit the tank with a shovel and it then sputtered started and ran. Now I am stuck at work since it wont stat.

I will go to get a relay but want the right thing for the right relay put in the right place.

the number on the big block with snap on fitting is Bosch 12077864. Is that the Pump relay or should I be looking elsewhere??


Thanks,

 

Your relay is on the driver's side of the firewall,but that is not your problem.
Your fuel pump is bad and that is why banging on the tank will get it going for a while. If you want to be sure the fan relay in the middle of the firewall is the same relay. Just switch them and if the heater/ac fan works on high your relay is good. I am 99% sure it is your pump and not your relay.Good Luck
Harry

 

Thanks for the input.

The two blocks, that I think are the relays, are side by side dead center on the firewall, slid down on adjacent metal clips. The wires coming out of them even look similar. I did swith those two and after the banging , as mentioned, it did run. I switched them back to no avail this time.
And I may have attached them in reverse order now.
What concerned me was that the "replacement" relay that was listed at the Advance store was not even close to the same size.
You think these are the relays and that they are probably good - by your respone.

I appreciate your response. Last year I replaced my safari throttle-body fuel pump for $95.00. A pain but not expensive. The $240 price tag make this a check everything else out first decision. There has to be an automotive engineer that can facilitate a design change so that the fuel tank does not have to be dropped.

Regards

 

Well, you could always pull up the carpet and cut a hole in the floor boards... LOL But yeah, I do agree that it is your fuel pump going out on you.

 

Is your tank side mounted between the frame rails? Like under the drivers passengers seat. If so, one bolt and on nut. Lift up and remove the brackets, loook out below. Dont forget to disconnect the hoses. Rar simple to drop in the newer body styles.