My dimmer switch dims my tail lights?

[krmill23]

I just bought a '67 C10 for just a few hundred dollars. It ran and drove, but it is very very rusty. For now my main goal is just getting it legal to drive to use just for utility. I have everything done except for the rear lights now.

I discovered this strange problem yesterday. When I turn the dimmer switch all the way up until it clicks, the tail lights go off. The farther I turn the dimmer switch down, the brighter the tail lights get. They just stay on too, no difference when I hit the brake. Any idea what this could be?

I also noticed that the left-rear tail light was much dimmer, and flashed alternatively to the right rear when I put the hazards on, so I took the left-rear tail light apart and discovered the yellow wire had pulled out of the "bulb connector" (not sure what it's called). I cut the wires and have that little part here now, but see no way to solder a new wire into there, it's like an inch long with two small holes going deep in there. I don't see any way to take it apart. Do they sell a part like this where it's already done with just short wires coming out so I can connect it up again real fast? I found the entire rear set on the American Autowire website for $100 after shipping, but I don't think I need to replace all of them. I'd rather just fix this part first.

Anyways, I think that's about the extent of my problems. I just installed a new alternator and universal ignition (the guy I bought it from didn't get it with keys so he hot wired it). Also did a few other things that have nothing to do with the electrical system so I won't mention them here.

Any help would be greatly appreciated!

[cdowns]

LOCAL AUYTOPArts store help section with electrical COMPONENTS STOP BY AND FAMILIZE YOURSELF WITH WHATS AVAILABLE FOR NOW AND FOR THE FUTURE YOU'LL SAVE YOURSELF MONEY AND TIME TOO

[krmill23]

Originally Posted by cdowns

LOCAL AUYTOPArts store help section with electrical COMPONENTS STOP BY AND FAMILIZE YOURSELF WITH WHATS AVAILABLE FOR NOW AND FOR THE FUTURE YOU'LL SAVE YOURSELF MONEY AND TIME TOO

Thanks for the reply cdowns! Yeah I suppose it could be anything for the tail light, and not the actual part that is supposed to go in there, if I'm not going to completely restore it or anything. I'll go get a universal tail light attachment and a tail light that will work.

That leaves the dimmer switch problem. Any idea what's going on there?

[67 chevelle]

Old and rusty = grounding issues , my 67 is fairly pristine as far as rust ,,,but,,, I had similar issues with the taillights , mostly because of bad grounding wires

[krmill23]

Originally Posted by 67 chevelle

Old and rusty = grounding issues , my 67 is fairly pristine as far as rust ,,,but,,, I had similar issues with the taillights , mostly because of bad grounding wires

Yeah I figured there were going to be some bad grounds, but it just seemed really strange to me that it would cause a problem with the dimmer switch controlling the tail lights. I'll take a look thanks.

Any other input or ideas would be greatly appreciated as well. Thanks guys!

[Jonlopes]

The dimmer in the headlight switch is for the brightness level of the dash lights and I think the click at the end of the turn is to control the interior cab light while the doors are closed. I think there may be a incorrectly routed wire or a short in your harness.

[krmill23]

Originally Posted by Jonlopes

The dimmer in the headlight switch is for the brightness level of the dash lights and I think the click at the end of the turn is to control the interior cab light while the doors are closed. I think there may be a incorrectly routed wire or a short in your harness.

Yeah this seems to make more sense to me, although I really hope it's just a bad ground.

[67 chevelle]

Originally Posted by krmill23

I just bought a '67 C10 for just a few hundred dollars. It ran and drove, but it is very very rusty. For now my main goal is just getting it legal to drive to use just for utility. I have everything done except for the rear lights now.

I discovered this strange problem yesterday. When I turn the dimmer switch all the way up until it clicks, the tail lights go off. The farther I turn the dimmer switch down, the brighter the tail lights get. They just stay on too, no difference when I hit the brake. Any idea what this could be?

I also noticed that the left-rear tail light was much dimmer, and flashed alternatively to the right rear when I put the hazards on, so I took the left-rear tail light apart and discovered the yellow wire had pulled out of the "bulb connector" (not sure what it's called). I cut the wires and have that little part here now, but see no way to solder a new wire into there, it's like an inch long with two small holes going deep in there. I don't see any way to take it apart. Do they sell a part like this where it's already done with just short wires coming out so I can connect it up again real fast? I found the entire rear set on the American Autowire website for $100 after shipping, but I don't think I need to replace all of them. I'd rather just fix this part first.

Anyways, I think that's about the extent of my problems. I just installed a new alternator and universal ignition (the guy I bought it from didn't get it with keys so he hot wired it). Also did a few other things that have nothing to do with the electrical system so I won't mention them here.

Any help would be greatly appreciated!

If you have a wooden bed there is a grind wire from the drivers side frame to the metal under the tailgate Make sure that's good
Posted via Mobile Device

[krmill23]

Originally Posted by 67 chevelle

If you have a wooden bed there is a grind wire from the drivers side frame to the metal under the tailgate Make sure that's good
Posted via Mobile Device

Nope, metal box. It's really rusty though, I almost put my foot right through it when I was cleaning all the moss and leaves out of it!

I found a nice thread on this site with all the locations of the grounds. I'll make sure those are all good first I suppose.

[krmill23]

So I made sure I had good grounds and grounded the body to the frame in 4 spots. I found a bunch of melted wires coming from the alternator and running along the front of the truck to the battery and replaced those. The brake lights weren't working but that was just a blown fuse, now they work. But still the dimmer switch controls the tail light dimness, one brighter than the other, and when the headlamp switch is pulled out, the left tail light is so bright there is no difference when I hit the brake.

I'm running out of ideas! Is it possible that this is the headlamp switch? I have the instrument cluster out it would be pretty easy to replace. Thanks for your input!