78 fuel guage stopped working! [Archive] - Team Camaro Tech

: 78 fuel guage stopped working!


smokinbarracuda
May 25th, 10, 02:25 PM
Hi, I'm having guage troubles and hope someone can help. The fuel guage, voltmeter, temp and tach aren't working. I think the temp and tach just need connecting to the motor and possibly the voltmeter. The main problem that i need to get fixed is the fuel guage. I recently swapped the guages over and its not been working since about that time. It can't be the guage itself though because i've tried 2 which behave the same. Basically it seems stuck on just below half full. I'm sure it's either a bad ground or the senders malfunctioned. By the way I'm no good with electrics so hopefully its a simple fix. I'd appreciate any help or suggestions.

Thanks

Everett#2390
May 25th, 10, 07:02 PM
Welcome, Gareth. In the body harness from the gauge, measure with an ohmmeter from ground to the tan wire - goes to the fuel sending unit in the tank - and you should read some resistance between 90 ohms (full) and zero (empty).

Not reading any resistance would mean an open circuit from the wire end to the black wire connecting to body ground by the tank. Sometimes a wire brush is needed to clean the wire lead and body for a good connection.

If you have resistance, then you need power from the battery/ ignition circuit to the other terminal on the gauge. Could be a blown fuse or a corroded fuse socket.

The above is for a GM product. If Chrysler, aka Barracuda, I don't know the wire color, but 90 ohms is empty and 240 ohms is full.

smokinbarracuda
May 27th, 10, 11:14 AM
Thanks Everett, I'll give that a go when I get chance. I'll need to pull the gauges again which I hate doing because everything this age is so fragile.