[bucko]

Just ordered a color wiring diagram for my 67; the headlights are not working; may be that both headlight low beams are burned out, so that will be the first thing I probe voltage for (at the connector for the headlight bulbs).

Also notice that when I pull the headlight switch to the first position (parking/dash lights), the gas gauge needle drops to the "E" mark; push it back in, and the gas gauge works normally again. Knowing that the sender in the gas tank is a variable resistor sending a ground, this tells me that the light switch is somehow supplying a ground to the cluster gas gauge. Maybe the cluster circuit "film" is bad. In searching this forum, I found the descriptions for the copper runs on the cluster film, so I'll look for ground shorting the gas gauge.

The fun begins.

 

[grampstoyz]

check your dimmer switch, I don't know if it would effect the gas gauge, but a bad or sticking switch can make your lights not work

 

[yellow69RS]

I agree with Gramps check the floor mounted dimmer then the headlights. The dash ground may be bad and when you pull the headlight switch the ground for the dash lights goes "away" causing your gas gage issue

Jeff

 

[68rs406]

The gas gauge/ cluster issue is classic 67-68 grounding strap not grounding the gauge cluster. There is a flat piece of metal or a wire from the gauge cluster that screws behind the gauges under the top center mounting screw of the cluster (if that makes sense). Rust, new paint, or missing wire will cause the issue you are seeing, check that out.


The headlights if they both just stopped working could be the floor dimmer, they get old and rusty and when they quit so do your headlights. If the high beams work I would suspect the floor switch.

I bet 9 times out of 10 on our old cars when there is an electrical problem it's a bad ground, from rust or new paint or missing grounds.
My car appeared to be a wiring mess when I bought it, but after cleaning up some bad wires and re securing grounds, it has worked like a champ for years now.
Check all grounds first and make sure they are good, it will save you headaches down the road too.

Good luck with it!

 

[bucko]

Thanks for the replies! I too suspect grounding issues. In doing a first time visual yesterday, I can already see a few grounds that have been disconnected; the two front grill turn signals for starts; I suspect there will be more.

 

[67sc]

See if the gauge light dimmer/brightener (or turn the knob) in the headlight switch makes a difference in the gas gauge level. He headlight switch has to have a good ground or funny things happen, if I recall...

 

[bucko]

When I turn the light switch to the left or right, the turn signal indicators light up; to the right, the right turn signal lights, to the left, the left turn signal lights up.