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Need help with dash


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9:47 PM
Dec 16, 2009
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Kansas City, MO
I was wondering if anyone can tell me what the three prong resistor looking device that plugs into the back of the dash cluster on a '66 or '67 Belvedere, Satellite, is and what it does?
Voltage limiter or regulator, can't remember which, but it controls the current into the gauges and someone will correct me if I am wrong.
OK thanks, could that effect the guages not working?
I used a test light on the fuel and temp guages and the light flashes, could that regulator be bad causing an interrupted signal, thus the guages not work?
test light on fuel guage is gonna flash
I am not very good with the electrical stuff, so why would the light flash on a fuel and temp guage?
By the way, my fuel guage is not working I am tring to find out why!:confused1:
DetMatt is correct, it's a voltage limiter and its function is not linear. It's a thermal device that interrupts the incoming 12 volts and has an internal heater that warms a bimetallic spring with a contact. When the bimetalic strip heat up it opens the contact causing an interruption in power flow. Then as it cools it makes contact again so the end result is a duty cycle or on/off signal producing an average 5-6 volts at the gauge. It's like a signal flasher. The slow reacting gauge doesn't see the on/off signal so it appears linear. If your test light is flashing then I'd say it's working. Grounding the sending unit wire on both the fuel gauge and temp gauge should cause the gauges to peg. Try that but don't hold to ground for too long. Response should only take a few seconds. If the temp gauge works when hooked back up to the sender and the fuel gauge doesn't then it's possible you have a sunk float on the fuel sending unit.
The sending unit is new and ohm's out correctly and the float floats. The guage worked briefly with the new sending unit, now it does not work. I have also changed the instrument cluster.
Any other suggestions?
Make sure that you have a good ground on your gas tank you can take a piece of wire with aligater clips on the ends hook one to the tank and the other to a good ground like the rear bumper or if you have along wire you cold go to the ground side of the battery. Also you can hook up a test light at the wire that gos to the tank unhook it to test with the key on it should flash as the gauge slowly gos up
Check the ground like mentioned above.

I know the cars originally ran a ground strap ( clip on ) that jumped over the rubber line between the pickup/sender to the steel fuel line. And if you've done away with the stock fuel line that's probably long gone.

I just painted my new tank and also painted the strap. I wanted to make sure the tank had a good ground.

I decided to solder a ground wire to the sender/pickup. I then ran it up through a grommet, along with my fuel pump wiring, into the trunk area and a good ground.

I just wrapped a wet cloth around the head of the pickup so the heat didn't travel and soldered it real fast with the BurnzOmatic.


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Sorry for not stating this earlier but the car has a fuel cell and the ground is good from the sender.
I seen something before about the instrument cluster has to be grounded, is this true? Could I just run a wire between the cluster and a ground under the dash?