I have a '55 2nd series Chevy truck. I've put a new wiring harness and tail lights in it along with a bunch of other stuff. The brake lights stopped working a couple of days ago, they worked fine before. I still have turn signals and hazards, but no brake lights and no parking lights. I traced them from the lights to the brake switch. The bulbs were good. The wiring, being brand new, is good. I sanded really well to get bare metal where the tail light brackets mount to the bed, I thought maybe it was a ground problem. That didn't do it. I got to looking closer at the brake switch. There is an orange wire (power from the headlight switch) and a white wire (tail lights). The orange wire got smashed against the underside of the floorboard by the brake pedal arm that goes into the master cylinder under the frame (almost cut in two type smashed). I figured, a ha, I've found the problem. I fixed the damaged wire but still no brake lights or running lights. I still have turn signals and hazards. Now that you know all that jibber jabber background, here's my question. Could the smashed (almost cut in two) orange power wire have shorted the brake switch? I would imagine that it would be shorted to ground all the time the brakes aren't applied when that brake pedal arm was smashing the wire against metal to metal. I can't find anything else wrong in the circuit, and since the turn signals work the same bulb as the brake lights, it leads me to think the switch got shorted. I figured I'd ask if that sounded right before I went out and wasted money on a brake switch I didn't need. I'm no electricmagician after all. What say you? As always, thanks for the help and thanks for this great forum!
I don't know how far back it goes, but the dash and tail lights started sharing a fuse so that if your tail fuse blew, you would have lost dash lighting and this stopped to fix it. You didn't mention dash lighting or fuses. How are they? Next, just because they are all bolted together doesn't mean there is a good ground path from body to ch***is to body to switch, etc. Do you have any ground straps connecting the body to the ch***is? It's good practice to have several. Any relays? Test the switch with a meter or test light and test the lights by disconnecting the switch and putting the wires together by hand.
I think you hit it. The dash lights were out too. I just ***umed the bulbs were bad, it was the first time I drove it at night since I rewired it. The only relay is a horn relay. The only fuse in the whole truck is on the headlight switch. I'm going to go check that. Thanks a bunch for the help.
Coincidentally I'm dealing with the exact same issue on my 59. Blinkers and hazards work, but no brake lights all of the sudden. Hopefully a new switch will do the trick for both of us!
The brake lights run/cancel thru the turn signal switch. I would start there and work ur way back. Good luck man, let me know how it turns out or any questions.
OK Scotty, here's what I know so far. The headlight switch is a repop and has a fuse at the back. The original headlight switch doesn't have a fuse. I pulled the fuse and checked it with the ohm meter and the fuse is good. Here is what is not working on the truck now: Brake lights Tail lamp running/park lights Dash lamps One low beam headlight (the other low beam works and both high beams work) Here is what does work: One low beam headlight and both high beams Both front turn signals Both rear turn signals Both front hazard flashers Both rear hazard flashers All gauges (Well, really only two- the ammeter and gas gauge. The temp and oil pressure are both mechanical as is the speedo and odometer.) High beam indicator light on the gauge panel Both turn signal indicator lights on the gauge panel The aftermarket stereo and two speakers I am unsure if the horn works, it still isn't wired to the horn ****on yet. The wire end is wrapped with electrical tape to prevent it from contacting any metal until I get it hooked up (that's a seperate issue, I'm having trouble with a Superior wheel and running the horn ****on wire). I KNOW FOR SURE all brake lights worked before (after I rewired the truck). I am not 100% sure if the dash lamps worked before but I think they did. Nothing has been moved, disconnected or otherwise damaged besides the mashed brake switch wire which is now fixed. To be quite honest, I thought for sure the fuse in the headlight switch would be blown. I don't have another fuse here to try out, but the ohm meter says this one is good anyway. I'm kind of at a loss as to why some circuits are working and some aren't when everything worked before. I guess the possibility exists the dash lamps and a low beam headlight could have blown when the brake switch wire got smashed, I haven't pulled them. But I know the tail lamps look good, I did pull those earlier to check. Thanks again everybody.
I'm no expert when it comes to electrical but I would get the tester out and start tracing where you have power and where you don't. Do you have power to that headlamp? Do you have power to the brake switch? Pull the terminals off and test the switch itself. If you take one thing at a time you should be able to track down your problem. Do you have a wiring diagram?
I'm going to go check the brake switch with the volt meter now. I'll report back with my findings. Thanks again everybody for the help!
I think you have a coupla problems. Easy one first, headlight. Ring bulb for ohms, two terminals should read to one, more to each other. Check against other bulb. Or plug in quick test headlamp. If just a bulb issue problem solved. Brakelight switch could have toasted when wire pinched. Hard to prove. Best test probably if you're splicing wire is to bare the switched wire or clip testor to exposed terminal on switch if available, operate switch look for indication of DC voltage cycling in unison.
OK guys, I got it fixed. Except the headlight and the dash lamps. The headlight low beam must've been burnt out all along. Like I said, I hadn't driven it at night pretty much since I got it. The dash lamps aren't working because I had to swap out for the old original headlight switch. The spring that controls the dash lamp dimmer function was broken long ago before I got the truck and they won't work without it. As it turns out, when the power wire going to the brake switch shorted, it burnt the contact on the headlight switch. And I mean burnt, like disitegrated! So, like I said, I swapped out the new repop (now useless) headlight switch for the old original one. I tested every light in every way- brakes, turn signals, hazards, brakes w/turn signals, brakes w/hazards, headlights on park lamps, headlights on w/turn signals, headlights on w/brakes, headlights on w/brakes & turn signals, and headlights on w/brakes & hazards. Everything is working like it should. Hooray for our side! Check out the pic I attached. The pointer is showing the burnt contact. It should look like the one on the other side. As you can see, it blew up, lol. I consider myself pretty lucky I didn't hurt any wiring or let the smoke out from that little escapade. The catalog places offer an add on factory style fuse box for around $30. I'd say that would be $30 well spent. That will be my next project. Thanks again for all the help. I really appreciate it.
the light switch has two circuit breakers in it, that part that burned off was one of them. Looks like a ****py repop that really ****s, it is supposed to just open the breaker (it will click until the short is fixed or the battery disconnected). I use old NOS or good used light switches, the repop stuff is junk. now you nkow
Thanks bud. I knew it was junk when I put it on. Side by side, the quality of the repop is horrible compared to the factory unit. I'm going to check with my guy at Dixie Truckworks and see if he has a good used factory piece. That's what I should've done to start with. Squirrel, you're a smart guy and I respect your opinion. I'm running regular factory lights (no new headlights) along with a factory heater (soon) and an aftermarket stereo with four speakers (the stereo has an inline fuse). No other electric stuff like power windows or spotlights or anything else like that. Do you think I should add the factory fuse box? Or will I be fine without it? Or, would the headlight switch burning up like that have been prevented when the brake switch wire shorted had there been a fuse box? Thanks again everybody for the help!
If you had a fuse box with a separate fuse for the brake lights, it would have helped out for this problem. Whether or not it's a good idea to install it...I would not bother. But you do need to make sure the wiring is all routed safely! I guess this experience taught you that already
Yeah, no kidding! I thought it was ok. But with bumps from driving and air blowing around under the truck, it moved that one wire just enough to cause a problem. I've got a zip tie on it to make sure it can't move. I might would have routed it differently had the wires been longer. There's not much room there to begin with. The wire was too short to go under the arm that works the switch, not enough room for the arm to move all the way. But with that factory style replacement harness I used, everything was already cut to length with terminals already crimped. It sure made it easy on me, but it would've been nice to be able to have a little more freedom to route things differently. The good news is that got me to thinking maybe I should give the rest of the wiring a good once over to make sure there weren't any other potential problems. And it was pretty easy to fix since I learned so much doing the rewire. And thanks again for the help Squirrel. Me and ****** Knuckles (Ron) were talking about you last night. There's a few guys here that are always ready to help somebody. P***ing down knowledge and expereince, answering tough questions, and being all around great guys. You're one of these guys and the hamb is a better place because of you and guys like you. I know you've helped me out more times than I can count and I've seen your insane post count and know most of it is helping others. So, thanks, I appreciate it! If you ever come to Concord, holler at me, beer's on me.
I'm glad you got that figured out. I just recently rewired my truck and your episode reminds me that I should probably crawl around underneath and give everything the once over again. FYI, the factory type add-on fuse panel was used just for extra accessories, like fog lamps, heater, radio etc. I added one to my truck but have yet to hook anything up to it. If you're going to add a heater and radio you could just use inline fuses but the fuse panel will definitely keep everything more organized and easier to access.
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