Good lesson on Grounding
 

Haven't done much with my 67 other than drive it for the last few years. Don't normally drive at night either but had to pick up some dog food so off I went. Got pulled over by police for having a fluctuating taillight! Really??? but still talked my way out of it.

Anyway, thought I would have a look and sure enough one side would dim while the other was flashing if the headlight were on. So, I changed the regulator (had one on the shelf). This made the voltage more stable on my volt gauge but didn't fix the tail light issue. Then took apart the tail lights and they were pretty corroded so I order new sockets and lenses from LMC. Took a look at the harness and it looked pretty cut up so I ordered a new one of those (front to back harness) and soldered the tail light harness breaks and shrink wrapped the wires. All looked good, got my new harness, sockets and lenses in. Power it up and ... worse than before! Now, both taillights would blink when any signal was on, I had no reverse lights but hazard lights worked. Put old harness back on-still bad.

Then got a battery charger out and hooked up to tail light harness and everything lit up fine with the negative clamp on the bumper and a +ve wire on the harness prongs-good get all the right lights working on each of the four prongs..

Long story short-Bad grounds on taillight assembly. I just thought I would put a wire from the bumper to the taillight screw on the lens and then everything worked light brand new. A good lesson for an old guy-Check the grounds even after you thought you had!

Of course, once I was under there, I started working on changing out the shocks. More to do...
:gmc2:

Re: Good lesson on Grounding
 

Good lesson! We keep learning. Thanks for sharing!

Re: Good lesson on Grounding
 

I am just about to jump on the restoration train, and I am considering installing a GROUND Circuit just like Bruce88 did on his epic build.

I know it will probably be a huge pain, and I know there are some items that have no ground wire(i.e., horn), but I am hoping it will help in the long run.

Glad that you found your problem, and that it was fairly simple.

Re: Good lesson on Grounding
 

Thanks-I still wonder why they just didn't run another wire down the harness for a ground to the tail lamp assembly-That would probably solve a lot of headaches for everyone. Of course, it's lasted for almost 50 years so I guess the frame ground was acceptable enough :)