Mechanics

CHEVY FUEL PUMP

2002 Chevrolet Venture

Electrical problem
2002 Chevy Venture 6 cyl Two Wheel Drive Automatic 175000 miles

had a fuel pump go bad in van when I changed it out the plug was burnt now that it is back together it will not start ! Have checked the relay switch and have checked all terminals to make sure they have power they do. Took the fuel tank back off and found that the grey wire in the harness that goes to fuel pump does not have any power going to it from the plug to engine I have by passed the computer and still no power need to find out the wiring diagram is or what the problem may be is the computer shot or when the plug burnt did it short the wire and where does the wire go? Please help ! Thank You
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Undertaker20057
July 17, 2010.



The GRAY wire you mentioned goes to the fuel pump. The other end of that wire goes to the fuel pump relay, which is locaed in the underhood fuse block. The relay gets it's power from the FUEL PUMP fuse (15A); also in the underhood fuse block.
Generally, this wire will have power on it for only about 2 seconds when the key is turned on and the engine is not cranked (spinning over). Then a timer cuts the power off. If the engine is being cranked the power continues when the engine starts to run.
Use a test light to check for power on the gray wire when the key is switched on (do not spin engine over). Light should come on for about 2 secs and then turn off. Also, check the black wire in the fuel pump wiring harness. It's a ground wire; make sure it is getting a good ground.
By the way, don't bypass the computer! Could cause other problems or even short out relays, blow fuses, damage computer, etc.

The gray wire goes to the relay terminal B5. You may have to backprobe this terminal to see if it has power when the key is first turned on.
A5

If this wire is burned, it could indicate a short in the wire. Check the wire at several places along it's length to see where it has power(remember it only has power for 2 secs when key is on, so you'll have to turn the key on and off several times during the tests). If it has power at a point closer to the relay but none at a point further from the relay, then the short is between those two points.

Freemba
Jul 17, 2010.