Fuel Gauge - Continuity

[Middleton]

Hi chaps,

Does anybody know whether there should be a small amount of electrical continuity between the fuel gauge white wire (which connects to the 'G' terminal) and the instrument cluster backing plate on a '72 bay?

I'm getting a resistance of 100 ohms, which is very weak continuity, but I'd assumed there should be no continuity at all because the white wire connects to the variable ground connection on the fuel sender, and this is isolated from the cluster backing plate at the terminal. The continuity must therefore be through the fuel gauge unit itself.

If it had full continuity with the cluster backing plate then it would be fully connected to ground and the fuel gauge would permanently be at the 'full' mark.

Here's a short clip for clarity. I test the brown wire first to show its lack of continuity, and then the white wire:



Thanks! Any advice is appreciated

 

[gagvanman]

You don't say what type of sender you have, but here is a diagram of the resistance at various fuel levels: