NeverSummer
Member
- Joined
- March 22, 2010
- Messages
- 15
- Reaction score
- 0
- City, State
- Santa Rosa, CA
- Year, Model & Trim Level
- 1992 XL
So like it says my fuel pump is not working because it is only getting half of battery voltage. I have searched all over the posts here and have not found anyone to have the same problem.
Lets start with the basics; The battery voltage is 12.5 (at chassis Ground), The voltage at fuel pump is 6.4, I hooked up a battery directly to the fuel pump and it runs. I trace the wires back up to the inertia shut off switch (btw i tested the switch and it works) still 6.4 volts. next place up the line is the PCM which the dark green/yellow wire has 6.4 volts. coming out of the PCM. I don't know where to go from there. the black/yellow wire from the power distribution box has 12.5 volts all the way to the relay, which I tested to be working from the FP lead of the VIP test connector, but triggering the relay is supposed to turn on the pump which it does not do.
I just changed the FP about a week ago because it was not working, nor was the sending unit. The FP worked for about a week then this.
Yes there is gas in the tank.
Any ideas? I'm desperate here!
Lets start with the basics; The battery voltage is 12.5 (at chassis Ground), The voltage at fuel pump is 6.4, I hooked up a battery directly to the fuel pump and it runs. I trace the wires back up to the inertia shut off switch (btw i tested the switch and it works) still 6.4 volts. next place up the line is the PCM which the dark green/yellow wire has 6.4 volts. coming out of the PCM. I don't know where to go from there. the black/yellow wire from the power distribution box has 12.5 volts all the way to the relay, which I tested to be working from the FP lead of the VIP test connector, but triggering the relay is supposed to turn on the pump which it does not do.
I just changed the FP about a week ago because it was not working, nor was the sending unit. The FP worked for about a week then this.
Yes there is gas in the tank.
Any ideas? I'm desperate here!