need help with fuel pump relay problem

the ignition key does not intergize fuel pump relay, but i can hook my test light to the positive side of battery and touch the green wire in the relay with test light and the relay kicks on and the vehicle will start. What do i need to do to fix this problem. please help me. thank You so much
:confused: :confused: :confused: :confused: :confused: :confused: :confused:

Year, make , model, & engine are necessary for help with diagnosis.

sorry new at this it is a 1992 4.3 eng s10 blazer

What is the 8th character in the VIN, (engine code)? Could be either a "Z" or a "W".

Orange wire at relay should have battery voltage at all times. "ECM B" 10 amp fuse.
Gray wire goes to fuel pump.
Black with white stripe must be less than 5 ohms to ground. (Relay trigger ground)
Dark green with a white stripe comes from ECM; must have battery voltage for 2 to 3 seconds when the ignition is turned to RUN position, and have battery voltage constantly with ignition in the START position. (Relay trigger)

thanks for the response I am lost the vin is Z the plug is what I have that you discribed . I changed the ign switch (new one) put on used comp. fried one jumping g&w wire ( leaked through alt. ) where should this wire get the volts to energize the relay for 2or3 sec.

Disconnect the fuel pump relay, check each of the wires in the harness connector. You must have the results indicated below:

Orange wire must have battery voltage at all times. (Comes from the "ECM B" 10 amp fuse.)

Gray wire goes to fuel pump. If you apply battery voltage to this wire, the pump must run.

Black with white stripe wire, resistance must be less than 5 ohms to ground. (This is the ground for the relay.)

Dark green with a white stripe wire comes from ECM to trigger the relay. It must have battery voltage for 2 to 3 seconds when the ignition is turned to RUN position, then drop to zero volts. It must have battery voltage continuously with the ignition in the START position. (Relay trigger)

When the relay is energized, it connects the orange wire to the grey wire. Post your results.

the switch doesn't do it's job is there a plug between comp. and switch to check ? I'm lost the relay unhooked checked out orange wire gray black &GREEN wire was dead unless I jumped it my self

Dark green with white stripe wire runs directly from the ECM terminal A1 to the fuel pump relay, no other connections.

Disconnect the relay, connect your voltmeter positive lead to the dark green/white wire in the relay harness. Connect the voltmeter negative lead to ground. Turn ignition switch to the RUN position and check for battery voltage for 2 to 3 seconds. Then turn ignition switch to the START position and check for constant battery voltage. Post your results.

I have nothing in run or start with switch I apreciate the help I have been complete lost with newer cars the green &white stripe wire was dead both sides of switch

What "switch" are you referring to?

If the green/white stripe wire doesn't have battery voltage in either ignition position, that is the problem. Check all ECM fuses, (both terminals of each fuse), with the voltmeter. If the fuses are good, check continuity of the green/white stripe wire with an ohmmeter from the ECM harness connector to the relay harness connector. It must be less than 5 ohms.

The ECM 1, (10amp fuse) feeds the pink with black stripe wire that runs to the ECM terminal B4.
Also, there is a pink wire at the ignition coil, it must show battery voltage when the ignition is in the RUN and START positions.

I still have trob. with this comp. Ijust came in the G&w wire was definitly broke some place . Iwill put it back together as soon as trace it I can't thank you enought
Just knowing where the g&W wire went with no conectors saved me . I am satisfided the problem is here.thanks again&again

Glad I could help. Post the problem/fix when you're done.

sorry I got excited the g&w wire was not broken nothing coming out of computer with ign switch in start or run position no volts

See post #10.

Also check ECM B 10 amp fuse, it should show battery voltage at all times.

Check pink/black wire at ECM terminal B4. It must show battery voltage when the ignition is in START and RUN positions. This wire comes from ECM 1 (10 amp fuse).

Post your results to all of these tests.

See post #10.

Also check ECM B 10 amp fuse, it should show battery voltage at all times.

Check pink/black wire at ECM terminal B4. It must show battery voltage when the ignition is in START and RUN positions. This wire comes from ECM 1 (10 amp fuse).

Post your results to all of these tests.

I think you might be posting over his head a few times there OM...

Where are you now there, llcope2? What have you been able to check? Do you have a multimeter? Besides a test light?

I took sat. off the blazer is my headace not my everday car
The ecm fuse is good I didn't say before but i'ts a 4 door when I jump the green&white stripe wire with the hot orange wire in relay & start the car
It seems silly but open any 1 of the doors over half way would kill motor if I
hurry and shut it it would stay runing .power windows mabe ground some where I'am going to check all wires again om is over my head I have o meter
but don't know under or over 5 test light just ground & hot for me I have run
ground straps to motor to frame to body even extra ones

It seems silly but open any 1 of the doors over half way would kill motor if I
hurry and shut it it would stay runing .power windows

This happen EVERY time???

The green/white stripe wire out of the ECM is the trigger for the fuel pump relay. The orange wire at the fuel pump relay should have battery voltage at all times. Don't jump the two together or the ECM could be damaged.

How the circuit works:
When the ignition is initially turned to the RUN position, the ECM applies voltage to the green/white stripe wire. The contacts in the relay close and connect the orange wire to the grey wire. The fuel pump is energized and primes the fuel system. During this 2 to 3 second time frame, the ECM watches for a signal from the ignition module. If no signal is received, the ECM shuts off voltage to the green/white stripe wire and the relay shuts off.

What to check:
1) At the ECM connector "B", terminal 4, is a pink/black stripe wire. This terminal must show battery voltage constantly whenever the ignition is in the RUN and START positions.

2) At the ECM connector "A", terminal 1, is the dark green/white stripe wire. This terminal must show battery voltage for 2 to 3 seconds when the ignition is initially turned to the RUN position. After 2 to 3 seconds voltage should drop to zero.

Do not disconnect the connectors at the ECM for either of these tests. Post your results to these two tests.

I checked the pink &black wire at the term. no volts in run or start nether did the g&white stripe wire nether shows volts
The fuse panel ecm always hot
I want to thank all of you for your patience:confused:

The ECM B 10 amp fuse is supposed to be hot at all times, that might be the fuse you're checking.

You need to check the ECM 1 10 amp fuse. It must show battery voltage in RUN and START positions only. If the ECM 1 10 amp fuse is good, the pink black stripe wire is broken somewhere between the fuse panel and the ECM connector B terminal 4.

problem fixed *********I have just came in I was busy till now the pink & blackstripe wire was it It starts every time I just ran a jumper wire
Now I'll go run a perm. one
Do I need to post anything else THANKS AGAIN ( FIXED ):smile: :smile: :smile: :smile: