I have a 97 Tahoe 4x4 with a 5.7 litre Vortec I'm working on. After the tranny was done the fuel pump won't shut off even with the key out. I swapped out the relay and no luck. I unplugged the oil switch behind the Cap and no luck. I lowered the tank and tested the pump harness. The grey wire is getting constant power with the key off. When you turn the key forward the purple wire gets power but the test light stays on weakley even after the first two seconds. Where does this purple wire get power from? I checked for pinched wires and shorts but nothing. With the key off though the purple wire is not getting any power. I'm stumped. Great site. Thanks for any help.
fuel pump won't shut off
- Thread starter floater
- Start date
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hassoun
Full Access Member
here is some info that could help you. i know you might not have a scanner to turn your fuel pump on and off but i believe those steps can be ignored.
The numbers below refer to the step numbers on the diagnostic table.
2. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step determines if the condition is located on the coil side or on the switch side of the circuit.
4. This step verifies that the PCM is providing voltage to the fuel pump relay.
5. This step tests for an open in the ground circuit to the fuel pump relay.
6. This step determines if a voltage is constantly being applied to the fuel pump relay.
12. You may need to remove the fuel tank in order to gain access to the fuel pump connector.
13. This step determines if the condition with the circuit is intermittent. If the fuse does not open, inspect the supply voltage circuit between the fuse and the fuel pump for an intermittent condition.
15. Use the same amperage fuse in the jumper as is used to protect the fuel pump circuit.
16. You may need to remove the fuel tank in order to gain access to the fuel pump connector.
17. Inspect the ground connection for the fuel pump. Be certain all ground connections are clean and tight.
The numbers below refer to the step numbers on the diagnostic table.
2. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step determines if the condition is located on the coil side or on the switch side of the circuit.
4. This step verifies that the PCM is providing voltage to the fuel pump relay.
5. This step tests for an open in the ground circuit to the fuel pump relay.
6. This step determines if a voltage is constantly being applied to the fuel pump relay.
12. You may need to remove the fuel tank in order to gain access to the fuel pump connector.
13. This step determines if the condition with the circuit is intermittent. If the fuse does not open, inspect the supply voltage circuit between the fuse and the fuel pump for an intermittent condition.
15. Use the same amperage fuse in the jumper as is used to protect the fuel pump circuit.
16. You may need to remove the fuel tank in order to gain access to the fuel pump connector.
17. Inspect the ground connection for the fuel pump. Be certain all ground connections are clean and tight.
Attachments
hassoun
Full Access Member
here is a good size page for you to read. attachments get resized.
http://hassounonline.com/floater1.gif
http://hassounonline.com/floater2.gif
http://hassounonline.com/floater1.gif
http://hassounonline.com/floater2.gif
