Mopar Action On-line – Tech Questions
Corey Carter, adairsville, GA, 1969 Plymouth Barracuda
Hey Rick, I have a 1969 Plymouth Barracuda Fastback with a340 4-BBL. I’m currently having an issue with my fuel gauge. It currentlyreads empty no matter how much fuel is actually in the tank. I read onlinethat my sending unit should give me 10 Ohms of resistance with a full tankand 75 to 90 Ohms with an empty tank (Depending on my sending unit). I wentahead and tested the resistance of my sending unit with a full tank and Iget a reading of 0.2 Ohms. This is far less than what a full tank shouldread. I could really use your help to find my problem. Thank You in advance,
P.S. All other gauges in my car operate normally
0.2 ohms is a shorted sending unit. Good chance this cooked the fuel gauge,and you’ll probably need to replace both. Quick test: Disconnect the wirefrom the sender, and measure the ignition-on voltage at the wire (to chassisground). It should pulse 0-12v-0-12v over a few seconds time. Stuck at zero?99%, cooked gauge, but a replacement will cook, too, until you install agood sender.