Open circuit at fuel sender

[fintubi]

Originally Posted by strictlypersonl

What happens when you ground the (harness) white wire where it connects at the tank connector? Ignition on.

Gage moves up to top of scale beyond Full, as expected.

[RockBit]

Bill:

Here are photos of the top of the tank and fuel sender from ERA812. I suspect the sender in your car is the same. There is no ground wire on the sender, the ground is established through the mounting screws to the tank. This is where the ground on my sender failed due to the sealant on the screw threads.

Since you are getting an open circuit between the white wire and ground, this indicates your sender is not grounded properly.

[fintubi]

Chris -

Thanks for the picture - very helpful.

In my case there's more than just the white wire coming from the sender. If it were only one wire, then I could see how effective grounding of the sender to the tank would be essential to get a meaningful resistance reading at the gauge.

But my tank harness has three wires, including a black that is presumably a dedicated ground connected to the sender body. So an open circuit across the black and white wires in the sender harness suggests to me that one or both of them is not connected properly at the tank end (or that there's an open in the sender itself).

Since I don't have the tank out of the car, so far I'm just looking at the plug end of the tank harness; I'll try to see if there's a way to see the other end by taking out the trunk bulkhead panel.

Bill

[patrickt]

Bill, are you familiar with this drawing of two versus three wire Smiths unit? It would be pretty hard to wire up the two-wire units without a pic as the connections are not intuitive.