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I have a 55 Chevy 2nd series and I have a couple of questions regarding the lights.

The dome light seems to be "hot" on both wires.
There are no door stops for lights so does that mean that the light switch is bad?

Also I checked the brake switch and it works correctly, but when I wired the only tail / brake light, when I press on the brakes, the dash lights come on.

Ok, so here is my question. I assume the light switch should ground somewhere, but if the switch was bad and not grounding correctly, would that cause my problem?

Other than that, the switch seems to work correctly; the head lights, the parking lights, the dash lights all work correctly.

thanks.

Sounds like you have one of the wires hooked up to a hot terminal when it should be on the ground terminal on the switch. One of the wires should be hooked up tp a terminalon thwdash side of the switch, that is connected to the rheostatthat controls the brightness of the dash . The 2 terminals that it should be connected are marked "D" and "GROUND" on the switch. You will have to have the switch out to see the markings. The dome lamp will only come on when the knob is turned fully counter-clockwise. Adding a door switch isn't too difficult, just splice in the ground wire with a momentary switch, run a wire to ground, and add a striker to the door in the appropriate location. I udes a 1/4" bolt and 2 nuts so it is adjustable.

the switch gets it's ground from being mounted to the metal dash, but mostly the lights only get power from the switch, and ground from their socket mountings

for the dome light, there should be one wire from the main light switch to the light, which is hot - the 2nd wire comes back to the switch and attaches to the variable resistor on the front of the switch which supplies the ground when the switch is rotated - in the off position the circuit is open - if you are measuring "hot" at the light, you're just measureing the same wire on both sides of the bulb, of the light doesn't turn off with the switch, the switch may be bad

for the brakes, power from the light switch goes to the brake switch, then straight back under the truck to the tail, and the tail ground is via the frame to the light assembly - nowhere will the dash light wiring intersect with the brake wire - got a shop manual? there's a wiring diagram in it

Bill

I can think of one scenario where it will. Power from the brake light switch goes to the brake light bulb but it finds no ground there. It then travels through the tail light filament, back up the tail light wire to the switch, where it is connected to the dash light circuit as well as the headlight circuit.

Clean your tail/brake light bulb and socket and the ground for it.

Edit: OOPS, not so with a task force headlight switch. Sorry for the confusion.

aww cletis - power going both ways on one wire??

the various circuits are independent, if it was gonna light up the dash lights wouldn't the light switch hafta be in the on position to get to that circuit? why doesn't it light up the park lights or any other light powered from the switch? switch broken inside?

I think most likely there's just wires connected wrong on the switch - and I found the page of it from the assy manual

Bill

you have a hot ground some ware

Thanks to everyone that replied. I will check the tail light, and thanks for the diagram so I can check the switch. I will check all of it and let you know.

There is a big auto show / swap meet Father's day weekend at Petti Jean Mountain in Morrilton AR, (about 30 miles from me) and I should be able to find some new parts.
It is a 5 day event and lots of stuff and good vendors.

thanks again.

Excuse me, I made a mistake. The head light, tail light and dash light circuits are not connected on a TF switch until the switch is closed. (head lights on) On some other switches they are. Sorry about the confusion.

May be you didn't make a total mistake, Cletis. Your scenario (bad ground on taillight assembly) works if the taillight and the dash lights are connected to the same lug on the switch, which is common, and the head and parking lights are on others. Of course, the lights connected to the other lugs would not light up.

My favorite question to answer my Marines when they are pulling out their hair on an electrical problem is "did you check the grounds?"... they usually dont come back.