Hello all, I have been working this problem for over a year now and for the life of me can not figure out what is going on. I replaced the dash pad in my 67 with factory rally gauges, and all the gauges worked just fine prior to the removal and install of the dash pad. Since the gauge pack cluster (Speedo, and gauge pack) had to come out for the dash, I unplugged the wiring, dropped the column, and removed the gauges. When I re-installed them, the fuel gauge now buries itself on the full side when the key turns on, and when I put the park lamps on, the right turn signal illuminates on the cluster. It acts as if it has a bad ground, but I even looped a new ground wire around the housing and made it 100% better than it was before.

What kills me is that everything worked perfectly when I took it out, and now this is happening. I would love to check the resistance of the fuel circuitry, but don't even know what I'm looking for. On my meter, all the connections on the printed board are showing between .02 and .04 ohms resistance when it is out of the car.

How would I know if the printed board itself is bad? it looks intact, its the original, has the Pontiac part # on it, and I have taken the thing all apart and put it back together so many times now I want to scream.

Ideas?????? Thanks!!!!

I think you have two problems assuming you did get a good ground at the instrument cluster. The turn signal light is a classic case of one of your parking light bulbs not being fully grounded. These bulbs contain two elements with the common between them grounded. If there is an inadequate ground, there is a sneak path of current between the parking light and the turn signal light. So when you energize the parking light, the current doesn't go to ground but rather travels up the turn signal wire. Happens all the time. I would pull each light bulb one at a time and use an alligator clip to go to a known ground. The other issue sounds like a bad ground at the fuel sensor.

BTW, where are you in Colorado, I am out here on business for the next few weeks. If not too far, I could potentially lend a hand.

Agree - classic example of a ground problem.

If it was my car, I would immediately suspect a grounding issue for the instrument panel, (the infamous metal wire and hoop at the upper center cluster screw) but you are confident you beefed that up. Try out Larry's suggestions and see what happens. The fuel gauge grounds to a screw at the front of the passenger side gas tank strap support.

Don't feel bad I had my gauges in and out 3-4 times after everything was painted up. Really sucks pulling it all back out again.

I learned it best to test all the gauges with a 9v battery, a couple alligator clips and a 100 ohm POT. (Not the AMP gauge though you will burn it up)

I found it easiest to test my fuel gauge starting at the wire in the trunk. There is a plug under the trunk latch with two wires. One is for the lamp for the licenses plate and the other to the gas sending unit.

Hope I remember this right but with the key on you should have 12V on the wire. With it pulled the needle of the gas gauge will swing all the way Full and with the wire grounded it will swing all the way empty or maybe its the other way around. Its a good place to start.

You don't state whether you swapped fuel tanks or fuel sender. My rally gauge was pegging full all the time as well. Ended up being a DOA brand new sender. Seller replaced it free of charge (parts wise) and new one works like it should.

Thanks guys... I will test the gauges out of the car. Also, as far as I know it is the stock 1967 sender and tank. The car was incredibly original when I got it 25 years ago and I have never had the tank out of it. I will check the wires in trunk too. It is just crazy that it only happened after I had the gauges out of the car. Stranger things have happened I guess. As a side note about the park lamp, I just checked the front lamps with the gauges out of the car and the right front does not come on when the switch is pulled. Going to change the bulb so see what happens there. Never would have thought to check that in a million years. I will throw a new bulb in it and let you guys know my findings.

That looks like it may be your problem. When you pulled the plug you removed the sneak path I discussed earlier. Replacing the bulb won't do it, you have to establish a good ground at the light, then the return path through the indicator disappears.

Still offering a hand if not too distant, I'm currently in Longmont, CO.

Sounds like the printed board on the instrument cluster is bad. They wear out and break where the plug is inserted. Also check the contacts on the plug to be sure that they are clean and get good contact..