Hello we just got this 86 s-10 blazer 2.8L 4x4 and fuel pump was bad! Well we replaced the pump today and still not pumping! I put 12 volts to the piggy tail wire by relay and still cant hear the pump coming on. Is there any thing that can be cause this pump not to come on besides the relay on this truck? Thanks RMitch

 

Wiring... Have you tested the wiring between the relay and the pump? Does the pump have a good ground.

 

I would check for you 12v at the pump, which you prolly wont get. Then check for 12v at the relay, and follow the grounds and clean them up with sandpaper and put some dielectric grease on them to fasten them back up. Also check the fuse, if its blown there you might have a short to ground from a pinched or worn through 12v wire, put a new fuse in, if it pops when you turn the key you have a short to chase.

 

Check your ECM B fuse.

 

Sorry, haven't been able to check the wiring between relay and pump, but im sure there is no voltage to pump from relay, because i dont hear the relay click when key is turned on, even though i have 12 volts to relay! I am interested in checking the ECM b fuse, but can u tell me where it is? Than if that's not the problem, I will take tank down again to check all wiring from relay to pump and harness. Thanks again Rmitch

BTW I did change out relay to see if it was bad!

 

fuse #29 in the fuse box under the dash on the left side.