I've got a '64 GTO. The fuel gauge is pinned past the full mark. It does this when the car is off and when it is running. It jumps to the left a hair when I start the car then darts right back to pinned. Is this electrical, ground maybe? Or is the sending unit shot?

I've got a '64 GTO. The fuel gauge is pinned past the full mark. It does this when the car is off and when it is running. It jumps to the left a hair when I start the car then darts right back to pinned. Is this electrical, ground maybe? Or is the sending unit shot?

Rex,

We went down this road awhile back with a '69.
One quick thing you can do to isolate the problem is disconnect the tan wire at the connector that goes to the sender and ground it, if your gauge is working it should come off full and stop at empty. Check the ground wire that comes from the sender and grounds to the chassis underneath, make sure it's a good ground. If your gauge is working you most likely have a bad sender. You have to drop the tank to remove it.
Do a search on this topic and you'll get more info. Good luck. ITO

Well, the problem seems to be escalating. Now my tail lights, brake lights, reverse lights and turn singnal indicator aren't working. Anyone have any ideas?

Just yesterday, I saw the gas gauge on my 68 GTO peg all the way to the right (out of sight to the right!) Ten minutes later it was back where it should be. This happened twice, both times the gauge returned to normal.

I thinks its terrorists ...


Bob Trimpe

I sounds like a bad ground if all these items have now suddenly quit on you, it's probably the best place to start trouble shooting.

We just replaced the sending unit in our 64 Lemans about 4 months ago. Shell Oil had a problem with too much sulphur getting into a batch of their gasoline, which we unfortunately must have gotten in our tank. The bad gas ate up the contacts on the sending unit, making the gauge needle peg all the way on full. What a pain in the butt!

The good news is that if you have to replace the sending unit, you can do so without dropping the gas tank. We filled up the tank and then drove the car about 300 miles to where we felt pretty sure that it was low on fuel. Then we jacked up the front end of the car, which made the remaining fuel run to the backof the tank. We then removed the sending unit without so much as a drop of gas coming out of the tank.

If you're experiencing problems with so many of the electrical components in the rear of the car, I would check out the ribbon harness from the fusebox back to where it plugs in under the rear seat. Take the rear seat out, get another harness and plug it into both connectors and see if things improve. Check the contact points in the harness and see if they are corroded or have a greenish buildup on them.

Also make sure you have the two grounding straps running between the motor and firewall and the one from the passenger side fender well to the frame. Your battery ground is connected to the motor, so it is imperative that your motor to firewall ground be a good one. You wouldn't believe the number of motorswappers who just leave these straps off inadvertantly and then wonder why they're having electrical problems.