2001 Pontiac Aztec no power to fuel pump

[njoehow]

Im not getting power to my fuel pump, just replaced fuel pump checked fuse its good ,I have constant power to the fuel pump relay but no power to the pump, replaced relay still no power i checked the relay terminals with key off, key on, and cranking still only constant power to the relay, non of the other terinals are activating, any help is appreciated

[aleekat]

Check for spark. If none, suspect crank sensor. If sensor doesn't sense rotation, pumps won't run.

[njoehow]

Yes I have already done that it has spark

[Tech II]

Disconnect harness to fuel pump...attach test light to the f/p circuit on the half of the harness going away from the tank(terminals B and C)......Turn key to on....test light should light for two seconds.......crank engine, test light should be on constant....this tests the relay and circuits to and from it.....

If it lights as described, the problem is in the tank......

If it doesn't light, double check C terminal in the harness for a good ground....can do this by leaving the test light attached to terminal B of the harness and ground the other end of the test light to a good ground....if it still doesn't light with key turned on, for 2 secs, or isn't on constant while cranking, your ground is probably good and you are not getting power on grey wire, circuit 120....if it does light, the problem is your ground circuit, #250(just splice in a redundant ground to it).....


If C terminal has a good ground and the test light doesn't light, put your hand on the fuel pump relay pump relay....have someone turn the key to "on"....did you feel the relay click?

If no, then you have either a bad relay, bad control circuit to the PCM, or bad PCM.....since you replaced the relay, it's not that...rare for a PCM....what I have seen is corrosion or connection problems in the Underhood Fuse Block.......

First pull the relay....

Then attach a test light to ground.....turn key to "on"....probe all 4 circuits with the test light......only one terminal should light(W12), power from f/p fuse.....there are three terminals left...probe one at a time, and have someone turn the key to crank....do it to all three terminals......one of them will light(V12)....the other two won't....now attach your test light to BAT....touch the other two terminals....one will be bright....that is W10.......the fourth terminal is V10, the power circuit to the f/p.....

One of those four circuits is your problem......If the relay didn't click in the previous test, you either didn't get BAT voltage at V12 with Key in crank position, or you have a bad ground at W10......this could be a bad connection in the fuse block....

If it did click, the V12 and W10 are ok.....and if you have constant voltage at W12, then circuit V10 is your problem(either open circuit in the line, or bad connection at the fuse block).....