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Q: 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.
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Are you getting ignition spark to the plugs? Some vehicles need to see this ignition signal before it will energize the fuel pump.
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?
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?
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!
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.
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.
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!
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