no power to fuel pump relay on 1992 Chevrolet S10 Blazer

My blazer stopped running. I replaced fuel pump, filter, and relay. The fuel pump didn't run when I turned the key on. I checked power at the relay and have .3 volts. I changed the pcm and I am still only getting .3 volts.

by in Corunna, MI on February 11, 2010
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
5 answers 10 comments
ANSWER by , February 11, 2010
Are you getting ignition spark to the plugs? Some vehicles need to see this ignition signal before it will energize the fuel pump.
COMMENT by , February 11, 2010
yes it is getting spark.
COMMENT by , February 11, 2010
I don't have a wiring diagram, but is this a 4 wire relay? If so, does it have the 12 volt signal and a good ground? And is it the signal from the PCM that is .3 volts?
COMMENT by , February 11, 2010
yes it is a four wire relay. their is .3 volts coming from the pcm on the orange wire which should be 12volts of constant power feeding the relay. The pcm, engine, and fuel pump all have a good ground.
COMMENT by , February 11, 2010
If you disconnect the relay and check the 4 terminals, you should have: 1. A good ground connection 2. A 12 volt signal with the key on 3. A wire that has continuity between the connector and the fuel pump 4. A wire between the connector and the PCM I wish I had a diagram to tell you which wire is which, but I think you have that figured out. Can you check all these and verify each wire is OK? Have you tried jumping power to the fuel pump and see if it runs?
COMMENT by , February 11, 2010
their is a good ground and continuity threw the wire to the fuel pump. there is no power on the other two wires. I did check the pump and it does run when it is powered up.
COMMENT by , February 11, 2010
Got it! I changed the ECMB fuse which at first appeared to be ok but after closer examination found it had blown.Blazer is running now. Thanks for the help!
COMMENT by , February 11, 2010
Great! The good news is the fuel pump probably caused the fuse to blow, so that may have needed replacement anyway. Please do me a favor, I am curious, how much did you spend on all the parts you replaced, and did you consider taking this to a shop to have it repaired? And why would you not take this to a shop? Thanks!
COMMENT by , February 16, 2010
So does this mean you're not going to answer my questions?
COMMENT by , March 04, 2010
Come on, not even a little help with my question?
ANSWER by , May 23, 2010
I had problems with the wiring . I replaced the wire to the relay that provides power. I also ran a new wire to the fuel pump from the relay.
ANSWER by , August 05, 2010
not applicable
ANSWER by , March 07, 2011
tie into the ground wire coming out of the wire harness coming out of tank and ground to the frame that fixed mine after several people were left scratching their heads
COMMENT by , February 15, 2014
This is not an answer, but when I hooked the ground up to the frame, does it matter if there is rust and what not or should I have sanded it down to bare metal?
ANSWER by , September 22, 2010
use a gm fule pump