47-59 i give up. i need help.

[mick53]

Don't let the smoke get out.

[mr48chev]

The only problem that I have seen with LED lights is that you have to have a special flasher or a resistance that matches regular bulbs to get the flasher to flash.

If the OP's turn signals work and the tail lights work. the Led lights aren't the issue. That is called process of elimination.

If the turn lights work ok that means that the wire from the turn switch to the tail lights is good. As long as both work independent of each other.

If the tail lights work and work when the turn lights are flashing that means that tail light wire is good and should mean that the grounds on the lights are good.

If the brake light switch provides power to a test light connected to the wire from the switch when you press the pedal and turns it off when you release the pedal that means that the brake light switch is working.

That leaves the actual problem in the turn switch it's self with something shorting across the board inside the switch or a crossed wire somewhere in the circuit.

By unplugging the turn signal switch plug down on the column and using taking a jumper wire to the proper pins for Brake/turn lights on the chassis side plug from the brake light switch wire he should be able to tell if brake lights come on on each side when he pushes the pedal.

I'm sorry gents but I can blow holes in 3/4 of your ideas you toss out as they have no bearing on the actual problem. Throwing out wild guesses never fix anything they just add to the confusion.

[nikwho]

Headlight switch sounds suspect right off the bat. If there are only two leads to the lights (one for parking lights, the other for stop/turn), then like you said, you know that the led's work. And, you know that the wire running from cab to light is good. I had similar problem with my '59. LED lights, Rebel Wire harness. I had brake lights that functioned, AND rear turn signals worked fine, but with EITHER R or L turn signal, both front blinkers would blink. Drove me nuts. Finally just replaced my turn signal switch, which was already brand new, and that finally fixed my issue.

Anyway, I'd look very closely at your headlight switch, as the power for all of these lights run through that switch. Secondly, I'd make certain that I was 100% certain that the turn signal switch was functioning correctly.

[evilokc]

Originally Posted by nikwho

Headlight switch sounds suspect right off the bat. If there are only two leads to the lights (one for parking lights, the other for stop/turn), then like you said, you know that the led's work. And, you know that the wire running from cab to light is good. I had similar problem with my '59. LED lights, Rebel Wire harness. I had brake lights that functioned, AND rear turn signals worked fine, but with EITHER R or L turn signal, both front blinkers would blink. Drove me nuts. Finally just replaced my turn signal switch, which was already brand new, and that finally fixed my issue.

Anyway, I'd look very closely at your headlight switch, as the power for all of these lights run through that switch. Secondly, I'd make certain that I was 100% certain that the turn signal switch was functioning correctly.

i just tested the turn signal switch and brake switch with a power light and they came out fine. i hadnt considered the headlight switch

[dsraven]

Brakes are usually powered with key off as well.
Disconnect rear lights and check the outputs of the signal switch. I say disconnect so you know the actual lights arent the issue. If the switch gives you power to 4 wires, 2 front 2 rear according to where the switch is placed, then test it again with the brakes applied or a jumper across the terminals on the brake switch. If your sig outputs are like they should be then turn on the lights and see what happens.of course report what you find. If all seems good up front at the switch then go to the rear and test each circuit with a regular old fashioned test light and no lights connected yet. If all circuits act like they should then look closer at the actual lights and their grounds.

[dsraven]

absolutely right mr48. problem is, evilkc hasn't gotten back to us with what exactly is going on with the circuits back there with the light taken out of the equation. do both circuits power up independently of each other. kinda sounds like it but no test results with the tail light unplugged and a test light used on each circuit independently. it's easier to start at the rear and do those tests first to eliminate an internal light housing wiring issue since that only takes minutes. if all good then go to the column like you are saying. it's a couple of minutes at the back bent down before sliding in on the floor on your belly or your back or cramped under the column. likely gonna end up there anyway but those couple of minutes out back are for peace of mind and verification
different folks troubleshoot different ways for different reasons but in the end usually get the same conclusions.

[dsraven]

Hey evil, curious what tail lights you have. A light with a socket like the old days and an led bulb goes into that or a light housing with an led sealed beam inserted?

[mr48chev]

Maybe Windows updated like it did on me and he lost all of his saved passwords in the process. That happened to me this week.

[1project2many]

LED lights can be much more complicated than folks realize. I once had a set of LED's that would behave similar to the problem described. At one point I put constant power to the LH and RH turn connections because, goldangit, that would make the lights light up. Except that when I got to the rear of the vehicle they weren't lit. Lots of checking and double checking but it finally took me getting tired of walking to ask a helper to watch the lights. "They're on. Wait, they just went off!" But I never did anything that should have turned them off! Turns out they would light for a few seconds and shut off. Bad connection? Bad chip? I dunno. Parts store only said they stopped selling those lights because they had too many problems.

I do not believe LED's should be treated like simple light bulbs. They are complex circuits sealed in plastic or epoxy and often cannot be tested internally. An incandescent test light is great to confirm the rest of the circuit is good. Then suspect the lights.

[mr48chev]

I have Led lights on both of my boat trailers with no problems. The big issue that I have seen is that even some special "led" flashers don't seem to work well with just led lights.

Still we can throw things on this around for ever and unless the OP comes back and gives us some feedback we don't what went on on his truck.

His Last Activity: 11-07-2021 07:29 PM A couple of hours after he posted the question.

[dsraven]

musta figured it out and is driving right now while we are sittin in front of a computer giving each other shots, haha

[evilokc]

hey guys. sorry i havent been back on after making this post. my wife got sick and i had no time. im reading all of your responses now,

[mr48chev]

Hope you wife gets well, thanks for the update.

When you get back to it, I'd figure out the color code of the stop/turn wires and unplug the tail light harness from the turn signal switch and make a jumper from the stop light switch to each turn wire in order. Yellow should be left stop/turn Green should be right stop/turn and brown should be tail.

That way you will know right of if the issue is wiring, lights or switch.

[evilokc]

Originally Posted by mr48chev

Hope you wife gets well, thanks for the update.

When you get back to it, I'd figure out the color code of the stop/turn wires and unplug the tail light harness from the turn signal switch and make a jumper from the stop light switch to each turn wire in order. Yellow should be left stop/turn Green should be right stop/turn and brown should be tail.

That way you will know right of if the issue is wiring, lights or switch.

that is correct. green, yelloow, brown to both.

[dsraven]

hope your wife is feeling better soon, or already, and no long lasting effects.
when you say your lights are sealed led units with only 2 wires then how does the sealed led unit get a ground? is the body of the light grounded somehow? does the sealed led unit have a plug in with only 2 wires or you are just referring to the 2 "hot" wires and there is still an actual ground wire that you didn't mention. please attach a pic of the light, a manufacturer part number, a link to a part online or something else we can look up to see what you actually have. it very well could be the signal switch but now you have peaked my interest to see what the heehaw you have for tail lights if they only have 2 wires.

[evilokc]

Originally Posted by dsraven

hope your wife is feeling better soon, or already, and no long lasting effects.
when you say your lights are sealed led units with only 2 wires then how does the sealed led unit get a ground? is the body of the light grounded somehow? does the sealed led unit have a plug in with only 2 wires or you are just referring to the 2 "hot" wires and there is still an actual ground wire that you didn't mention. please attach a pic of the light, a manufacturer part number, a link to a part online or something else we can look up to see what you actually have. it very well could be the signal switch but now you have peaked my interest to see what the heehaw you have for tail lights if they only have 2 wires.

sorry. yes there are two power wires and a ground.

[mr48chev]

Well maybe no one saw my put on the wrong thread post.

[evilokc]

okay im starting at the beginning again. with the key ON and the brake pressed i have power at the white and orange wires on the columb. let off the pedal and power goes away. i believe that means the turn signal switch is working correctly. with the key on and the brake pedal NOT depressed i have power on only one terminal of the brake switch. with the brake pedal depressed i have power to both terminals on the brake switch. i believe that means the brake switch is good.

[mr48chev]

The only reason that the headlight switch would have anything to do with the stop lights is if the bi-mental spring in the switch overheated and shut the power off. This is on an original wiring harness where the light switch works as the connection block rather than running everything to an aftermarket fuse block.

I'm believing that the brake light wire runs to the fuse block and not the headlight switch.

Lets go back to the first post and start over.

To quote Evilokc:
i have a 53 chevy with an EZ wiring harness. i didn't install the wiring which was a big mistake. you can't trust anyone anymore. the issue is the brake lights. they have been working for years and now they don't.

the lights themselves are LED with the tail, brake, and turn all using the same leds. the taillights still light up. the turn signals still work but when i hit the brake nothing happens. my first thought was brake switch.

I tested it with a power light and its good. not believing it i replaced it anyway with a new one that tested good but still no brake lights. at the rear light plug there are two wires per side. one for power the other for turn signal. with the taillights on the power wire has power. with the turn signal on they both have power.

I push the brake and both wires lose power. the tech line said to check the wires from the steering column to the brake switch and its good. then they said check brake switch and its good. then they said if both of those are good then you have brake lights. I don't though. I'm out of ideas. I've started pulling the two wires out of the loom the whole length of the harness to see if i can find anything. since they have power individually, I can't imagine what i would find? the only thing i can think to do that i haven't is to run two new wires from the fuse panel to the brake light plug to see what happens. again, since everything has power, I don't know what I'm expecting to be different. ideas would be greatly appreciated. this has gone on far too long.



Turn signals seem to work without an apparent issue. That eliminates the turn signal/stop light wire

Taillights seem to work without an issue and the turn lights work when the taillights are on, I assume.

There could be a ground issue though. Bad grounds will sometimes cause the turn or tail to ground though the other side.

Meaning before you go further check your grounds to your taillights. I'd run an extra ground wire to clean bare metal on the frame and not totally trust the bed to be grounded right.

That brings things back to the internal connections in the turn signal switch. I'm still not convinced that the turn signal switch itself isn't part of the issue.

I'm thinking that the brake lights don't work if you have the 4 way flasher switch on and don't work at all if you don't have a flasher in the 4 way plug and have the switch on. It works fine if the 4 way switch is off though. That is the way it works on a 77 Ford F-250 but I am not sure on a mid 70's Chevy. You do have a working 4 way flasher in place?

[dsraven]

Hey evil, are you able to post a pic of the actual lights and the wiring going to them?
Can you explain how you are testing, what kinda tester and where do you connect the ground? Have you traced the wiring back from the lights, does each light have a tail light wire that goes to the front or is there a T slice somewhere near the back where the single tail light wire gets split and one goes left, the other right? Sometimes those are a problem because they dont get sealed up well and corrode so there is resistance. Led lights like to run in a narrow range of voltage so resistance can mess with them. Same for the grounds, a ground is actually an extension of the negative battery terminal but instead of running a ground wire to everything it relies on many connections that are unprotected from the elements because "it's just a ground" and wont arc like a positive wire would. if the connection to an actual good ground has resistance it messes with the led's available voltage just like a poor wire connection would. It's just that, unlike an old incandescent bulb that would simply run dim, an led simply wont light up. Like mentioned, the light housing or wire can have an awesome ground to the box but if the box has a poor connection to the frame, well you get the idea. It's why I suggest to use a test light with some amp draw. An old fashioned tester may light up dim which tells you there is a poor connection. An electronic tester will light up because it senses voltage but any kind of draw on that circuit and the circuit fails. Also, like mentioned earlier, the tail light circuit is independant of the signals so if there is a problem involving both circuits at the appliance, light, then it makes sense to remove the appliance from the circuit, test each circuit, then check the common ground.
Just some ideas to test if you are still having issues.

[MiraclePieCo]

Brake lights are typically just both L&R turn signals applied at once. The problem can likely be found in your turn signal circuit.