fuel gauge voltage limiter
 

Hi Guys, I have a 1969 Road Runner and the problem I have is neither the fuel or temp gauge is working. Having read a number of other similar issues posted it sounded like the voltage limiter was the issue. I replaced it and still nothing. One of my questions is does the limiter have to be grounded. The new limiter has a flange of the back which looks as if it would be grounded versus the old one which does not have this flange. This is a new car to me so I really would appreciate any help.
Thanks Keith

I believe it does (need a ground), but not absolutely sure. I also don't remember the layout of your panel, but "in general" here are some of the issues with these panels

If yours uses a connector to disconnect the harness from the PC board(s) suspect that the pins on the board may be loose / corroded and solder them to the board, and of course while you are at it, "work" the connector on/ off to scrub the contacts clean, make sure EVERY connector terminal is a tight fit on the pins

On my Dart, the spring contacts for the limiter are only connected to the board by spring and friction. Turns out they were not making contact with the board. I soldered from the spring contacts to the board traces. A better way would be to cut small gauge "jumper" wires and solder them to the board and jumper and solder to the spring clips.

Also on mine, at least one of the gauge studs/ nuts was not making contact. Work the nuts loose/ tight several times

Better yet, pull the entire dash apart and clean the copper board as well as the contact points (grounding screws) in the casting.

Make SURE you have a good ground jumper wire from the cluster casting and or PC board to a good ground

The copper erodes on some boards where the panel light sockets "spring" in, and this can lead of course to lighting problems

Last, remember that the temp sender wire goes through the bulkhead connector, and these are a huge problem for many, nowadays, for corrosion, and damaged connectors.

The fuel sender wire goes down through the connector at the left kick panel on the way to the rear, and this is not so bad, but it would pay to check it, at the very least, "work" it in/ out a few times, again, to scrub the connection clean.

And of course check the sender connector for tight/ rust/ etc, and make sure the tank is grounded.

My 1970 Coronet/Charger Service Manual shows in the electrical schematic 12V feed, 5V to the oil, fuel and temp gauges and a tab marked ground. My instrument cluster is out and on the shelf, that tab is spot welded to the limiters case bends down 90' and plugs into a slot in the circuit board and traces to all the grounds of the bulbs and gauges. All that tells me your answer is yes, the limiter's case must be grounded.

Thank you guys! I will try both your suggestions. Looks like a little more work will need to be done than simply plugging in a new limiter.

I'm having the exact same problem in my '72 Satellite, tried a new voltage regulator but the gauges still don't work. I was wondering about the extra prong on the casing because the original regulator doesn't have it, so I'll try hooking it up to ground. If that doesn't work, Racer Hog sent some great photos of a resistor he installed with a capacitor in place of the voltage regulator so I'll try that.

2 questions:
Does your regulator also have a round condenser mounted next to it that shares a slot with one of the prongs? Mine has one with a paper insulator on the prong, not sure if that's the problem

What's the best way to clean the copper leads on the back of the panel?.

68 Plymouth Fuel Gauge Voltage Limiter
 

I have a 1968 Plymouth Satellite which carries a 440. My fuel gauge is not working but the temp gauge is. Based on what I have read, if both were not working then it is likely the voltage limiter. But since the temp gauge is working I assume it is something else. Can anyone share thoughts on what it could be. The fuel sending unit is good in the tank so don't think it is that. Maybe the fuel gauge itself. Any test I can do to isolate the problem. Any help would be appreciated.