Identify three wires going to fuel tank on 1989 convertible with throttle body fuel injection

[JensenHealey]

The 1989 convertible with the throttle body fuel injection has an in-the-tank fuel pump. I want to see if it is getting power when I crank the motor but I have to know which wire does what. Here is a photo of the modular harness plug going to the fuel tank. One wire is red and another wire is a lighter color and the third wire is too obscured with undercoating to tell what color it is.

Anyone know which wire does what?

[IndyJimW]

IF it uses the Caprice fuel pump the book says -

Pink is fuel gauge

Black or Black\White is ground

? is fuel pump. Diagram does not show color of wire.

Hey but two out of three ain't bad.

Good luck,

Jim Wood

[IndyJimW]

When you turn on the ignition, power is supplied by the fuel pump relay to the fuel pump for 2 seconds.

If the fuel pump relay is working have someone turn the key on while you test for voltage for the 2 seconds.

If the relay is bad or missing jump the relay and supply a constant voltage, but it may be hard to tell the pump from the gauge.

Good luck,

Jim Wood

Edited February 1, 2021 by IndyJimW

[JensenHealey]

I will try cleaning the undercoating off the wires and after that I will try to get a friend to help turning the key while I am under the car checking for an electrical signal. Thanks for the hints on the wire colors.

[JensenHealey]

I cleaned as much of the undercoating off the wires going to the fuel tank on the 1989 convertible so I could try to identify the wire colors.

This is what I ended up with:

Edited February 3, 2021 by JensenHealey

[IndyJimW]

Do you have power or grounds at the wires?

 

Good luck,

Jim Wood