78 F-100 Gauge Wiring question

[78FordF100]

Hello to all,

I am new to the site and can't wait to learn from it. My question is that I have a 78 Ford F100 truck with a 302. My instrument cluster has all gauges and only the fuel gauge works on it. The previous owner put a cheap gauge set and had the oil amd temp gauge working. Would like to get the original gauges wired back up. From what little I have been able to find was that were red wires with white and white wires with red that controlled part of it.
Yeah alot huh!! Headed outside today to check the harness and need kind of a starting point. Thanks in advance!

 

[Mil1ion]

Fuel sending units and ICVR's fail
The float may fill of fuel and sink showing empty.
The ground to the SU could be lost due to the fuel tank and SU connection being rusted losing ground.

It appears your ICVR works if you have the temp gauge working,therefore the issue will be the SU and ground.
Empty and Remove the tank remove the SU using a BRASS PUNCH to avoid sparks lighting up the fuel tank.

Inspect the grounding locations of the tanks and the float for a hole in it.
Next would be the resister on the SU. You can perform bench test on the SU using a 9 volts battery.

 

[Mil1ion]