bRAKE LIGHTS.

[DAYDAY]

My tail lights burn bright when the light switch is engaged and burned normal in the parking mode. brake switch tested good and grounds around the light bezel cleaned well. any help would be appreciated.

[The Rocknrod]

Just FYI, there is a FAQ section that addresses electrical issues like yours "Electrical Threads:"
http://67-72chevytrucks.com/vboard/s...d.php?t=646002
Your welcome.

[DAYDAY]

Thanks rocknrod. New to the site finding my way. Thanks again for your time.

[jchav62]

That's an interesting issue. Are the bulbs fairly new?

[DAYDAY]

Brand new.

[Rust-O-Matic]

I don't completely understand your description. Are you saying they are brighter than they are supposed to be when the lights are switched on, as if the brake is on?

I had a bunch of really strange stuff going on with my tail lights due to poor ground, so I would suggest starting there. Mine would work fine until I'd hit the brakes with the parking lights on, and one light would go out. Sometimes one side would look brighter than the other as well. Really weird.

I put complete new light and bezel assemblies in, and they still didn't work right. So I took them back out, removed the little J-nut type clips that the screws go into, sanded the clips clean, sanded the metal they attach to clean, then reinstalled everything using new screws. #10 sheet metal screws, I believe. After that they work like new.

[DAYDAY]

Yep, when i pull the lights on they light up like the brake is applied. i to sanded the j nuts and the metal on the bed. bulbs are new. gonna try and run some grounds from bezel to frame rails and try that. also the park lights quit at the same time. Thnaks for your time.

[aerotruk63]

Check your ground straps from engine to frame, engine to cab, frame to box.

[DAYDAY]

i will do! will the ground from engine come off the block in the back? other threads said that their problems were caused by bad grounds. gonna jump on it saturday. thanks for your time.

[aerotruk63]

From the 1963 Custom Accessories Manual for Radio Installation. JUST GROUND EVERYTHING ! lol

[Rust-O-Matic]

So when you actually push the brake pedal, do the lights dim back down to normal brightness? And do the turn signals flash dim as well? If so, it just sounds the wrong filaments are lighting up. 1 wire powers the brake/turn signal filament in each bulb, and a separate wire powers the parking light filament. Are you sure these wires aren't switched somewhere? If the sockets have been replaced at some point, the wires could be flipped around backwards. I don't think you can put the bulb in the socket backwards.

[DAYDAY]

Thanks so much aerotruk63. I plan on getting on this saturday.....hopefully. Thanks for the diagrams.

[DAYDAY]

Rustomatic i changed the pl;astic thing that has the brass contacts that fits into the socket. I have reversed the wires multiple ways to check.the only time i have been able to get them to burn normal was when the light switch was in the park light mode. Thanks.

[DAYDAY]

Oh and the signal light don't burn at all. Thanks rust o matic.

[Rust-O-Matic]

Ok, here's what I would do to narrow it down a little further. First, verify power to each contact in the socket. Remove a light and pull the bulb so you get to the contacts inside the socket with a test light (or voltmeter). Now pull the light switch out to the parking light position (or all the way out for headlights, doesn't matter which for tail lights). Ground the test light and touch the probe end to each of the contacts in the socket. One of them should light the test light up. It sounds like you've got power to this one now, based on your description. On a side note, your front parking lights should come on when the switch is in the parking light position, but go out when the switch is pulled out all the way to the headlight position.

Next, turn the lights back off. Now push the brake pedal down and wedge something against it to hold it there (so the brake lights come on). Go back with your test light and do the same process to both contacts in the socket. The other contact should light up this time, and verify that you have continuity from the fuse box, through the brake switch, to the rear lights. If not, make sure you are getting power to the brake switch under the dash, and follow the wires back toward the fuse box to see where the juice stops.

Once you sort that out, then do the same process using the turn signal. Turn the signal on, and put your test light to the same contact in the socket that the brake pedal made light up. The test light should blink. If not, then check the signal switch and related wiring at the column/dash for problems. If your front signals are working, or at least lighting up when the signal is on (I can't remember if they blink real fast or just stay on solid when a rear one is out) then you can assume the switch and dash wiring is ok, and the break in continuity is probably between the firewall and the tail lights.

Once you verify that each of these 3 items provides power to the two terminals in the socket, you can focus on the ground and the lights themselves. The only thing that can cause the bulbs not to light up at this point is either the wrong bulb is installed (1156 in an 1157 socket, or something like that), or bad ground from the socket to the truck bed (assuming the bed is grounded to the chassis and/or battery). The socket gets its ground from the light housing, which gets its ground from the screws and J-clips that hold it in, like we talked about earlier.

Phewwwww that was long-winded! Good luck. Let us know what you find out this weekend.

[DAYDAY]

1157 is the correct bulb right? Thanks for your time and help. Rust o matic.

[Rust-O-Matic]

Yes sir, 1157 is the correct bulb.

[DAYDAY]

Sorry for a non reply but life sometimes gets in the way. the problem was the tail lamp rear harness was faulty. eraw spots in the wires where they connect together.Thanks for all of you guys help!.

[Rust-O-Matic]

Man I forgot all about this thread. Glad to hear you got it fixed though!

It sounds like mine is being hailed on as we speak. I gotta build a bigger garage. Or move out of tornado alley...