Fuel tank sending unit problem

[Oleguy 74]

the wire from gauge is probaly grounded some where from plug to gauge.go tosea biscuit68.tripod.com.look at wiring diagram for the year of your bronco.

 

[DirtDonk]

Yep, what Oleguy said.
You now have to trace the entire circuit AND the gauge because it's new and you don't know if it's part of the issue until you check. But you're probably lucky in that it's just one of the wires buggered up.
Follow the entire rear harness along the frame and up to the firewall to look for any damage from dual exhaust, careless work underneath, or perhaps even damage from flying debris.
Don't ignore the connector at the end either and make sure nothing of your old jumper wire is still remaining in the contact holes.

I'm not sure the easiest methods to check these wires electrically would be, but others probably have some simple tests in mind that might save you some time.

Paul

 

[eslusser]

Ok thanks. Is the wire from the sending unit to the gauge a single uninterrupted wire? If I can’t find any issue along the wire route, can I just run a new wire straight from sending unit plug to the back of the gauge?

 

[DirtDonk]

No and yes. No it's not an uninterrupted wire, but yes you can wire it that way with a new one if the old one turns out to be the problem.

Because all Broncos had the option of 2 gas tanks, all the harnesses had an intermediate connection under the dash where the assemblers could insert a selector switch and secondary wiring for the aux tank.
This is in the form of a funky looking 90° push-together thingy along the Orange wire for the tank sender.
You could start your checking at that connection to see if it's shorting out on something.

Paul