Fuel Gauge Sending Unit - Voltage?

[Bullitt]

I've done the usual checks to see if the gauge or sending unit is the problem:

Grounding wire to chassis doesn't make the gauge go to full
Different sending unit doesn't work either

I've checked voltage at the sending unit wire with power on. I get 5.5 Volts. What should I be getting???

I tested the gauge recently when it was out of the car and it swung to full when i jumpered the right wires on the back, so I'm pretty sure it's not the problem...

FYI - I've got a JME cluster with Autometer Phantom gauges. Everything has worked pretty well for ~8 yrs now, but now have this problem.

Any help would be appreciated!!!

 

[ForceFed70]

Wiring from sending unit to guage?

 

[Bullitt]

Wiring from sending unit to guage?

yes, that's the one I'm talking about. I know the gauge works off the variable resistance in the sending unit. I was expecting to see 12V, not 5.5V and want to confirm that it is getting the right voltage at the sending unit...

 

[gtss]

5.5 V sounds about right, if you check with a test light you should find it pulsating, that is what the IVR puts out

when you grounded the signal wire- did you ground it near the sender so it is testing the full guage circuit because from what you are explaining it all sounds like it should work

What is the initial symptom with the guage? could the float be binding on something in the tank?
gtss

 

[Bullitt]

Yeah, I grounded it to the tank itself and also tried grounding it to different points on the chassis.

Very odd...... Maybe pull the cluster again and check the gauge....

 

[10secgoal]

You have a broken wire from gauge to sender sir !
To test disconnect wire from gauge to sender, make new wire to ground gauge right at the dash. if it worky, wire is proven bad.

 

[ForceFed70]

You have a broken wire from gauge to sender sir !
To test disconnect wire from gauge to sender, make new wire to ground gauge right at the dash. if it worky, wire is proven bad.

If he's measuring 5.5V at the sender, the wire/connection isn't completely broken. But it could be a poor conection which would introduce a bunch of resistance to the circuit, added resistance would make the guage not work correctly.

 

[Bullitt]

Thanks for the replies, will be digging into the dash (again) this weekend.