Fuel Gauge

JCastellaw · #1 (**permalink**) 01-12-2008, 04:25 PM

My friend has a 74 bronco and the sending unit is not getting any current to the sending unit. I checked the fuse panel and all fuses are hot. Is it the gauge? Any way to check without going behind the dash?

fordtrucksforever · #2 (**permalink**) 01-13-2008, 03:01 AM

Check resistance on the sending unit. It should be between 10 and 90 ohms, give or take... Then check continuity on the wire(s) running to dash.

RCrawler · #3 (**permalink**) 01-13-2008, 11:16 PM

You're not getting any voltage at the sending unit wires? Do you have a good ground? Ground seems to be the most common problem that I find.

Are any of the other gauges malfunctioning? The fuel, temp and oil psi gauge get reduced voltage power from a voltage regulator (about 5-6 volts, as I recall).
Check for input voltage at the gauge and then check the stud that goes to the sender. If you have voltage in but nothing out, the gauge is bad. Since dual tanks were an option, the wiring is made so that a jumper harness could be installed to use the switch. Make sure that the wire from the gauge to the harness is plugged in. If this is the same Bronco from your post about dual tanks/ no switch, It may be possible that they disconnected the wiring with the intent of adding a switch.

Jason

JCastellaw · #4 (**permalink**) 01-14-2008, 01:35 PM

Thanks!
No Heat at the sending cause I checked it. I would think that the ground wouldnt matter with a test light!

RCrawler · #5 (**permalink**) 01-14-2008, 08:25 PM

As long as the gator clip end has a good ground...

Since you don't have power at the sending unit, go back and check the input and output of the gauge.

Jason