47-59 LED turn signal issue

[Rickysnickers]

One of our posters was having an issue with his LEDs. Here's a thread I started a while back. Please feel free to comment on it, as I would like to get my issue taken care of as well. ANY help is appreciated.

https://67-72chevytrucks.com/vboard/...d.php?t=825376

[joedoh]

radio shack used to sell 10 ohm sand resistors, high wattage (20-50w) resistors packed in sand for heat dissipation. you wired them in like the bulbs, one side to ground and the other to the signal wire. it mimicked the load of a filament bulb. radio shacks are gone here but you may still have one.

i have seen the same thing at auto parts stores, called load resistors, in the bulb aisle.

this brings up a third point. tudoraz used a new wiring harness in his build and his flasher socket was actually wired backwards, which wouldnt matter with a metal can flasher but absolutely matters with an LED/solid state flasher. if you are using a new harness, make some jumpers with spade ends switch the polarity of the LED flasher.

[72Mountaineer]

Something similar happened when I went to LEDs. I also bought 2 flashers with ground wires, things were still wrong. As I remember, my flashers would work but the blinkers wouldn't. I got to looking at the "in-out" of the wires that power the flashers and found out that though they were installed in the fuse box correctly, the current was going the opposite way in one of them, the blinker one. I made 2 jumper-type wires and removed the flasher and used the jumper wires opposite of how they would be when pushed into the fuse box....and everything worked. Apparently typical flashers work in any direction but the LED flashers do not. I bought a non-directional LED flasher and it cured my problem. If you're at your wits end (as I am with a brake problem), you'll try anything. Good luck.

[mr48chev]

He hasn't been back on the board since the day he posted the question.

[Rickysnickers]

I am here and here everyday, sometimes several times

[mr48chev]

The original poster of the thread that he asked the question on his LED brake/ turn light issue had not been back on the board since The 7th at the time I posted that last night.

The thing is that with any electrical problem you have to stop and isolate the problem

The first step is usually the question of "what did I just add or what did I just change?

The second step for me on any truck that I didn't do all of the wiring on is to slide under the back and see if anyone else has wired up a trailer light plug on it. I've lost track of how many trucks with stop/turn/ tail light issues I have cut a basket of snakes trailer wire hookup out of and cleaned up and taped the wires on. I've got one of my own that I need to do that on right now as in a previous life someone wired the tail lights and a trailer plug with a length of yellow extension cord like is often used on construction jobs. That is my 77 dually flatbed that usually only goes to the dump every few weeks right now.

[Rickysnickers]

Ok, sorry. I thought you were referring to me. I'm dealing with some family issues. I won't be able to really do anything today, but maybe Friday or this weekend. Oh, I was under it the other day. There's no trailer hook ups or anything like that. I am going to concentrate on the front as that was the last thing that was added.

[mr48chev]

No trailer hookups is a good thing, that is one check mark on the elimination list.

I'm and old mechanic and high school auto shop teacher. I always tried to teach my students to do their trouble shooting in a methodical manner and eliminate or cross off things from the list. All too often people aren't looking at the real picture and checking off what works to find what isn't actually working.

Most of the time with lights on a truck a good test light and a decent multi meter are about all you need to check your system. Then it is usually a case of "I have power here but I don't have it there, Why?".

[Rickysnickers]

Update for you all. I had some time yesterday so I looked around to see what I could see. The issue ended up being a grounding problem and relay. The ground wire coming from each of the front turn signals, was not contacting bare metal. That problem taken care of. Now I have two different relays for the hazard and turn signals. I started the truck and the turn signals were still doing the fast, irregular blinking. However, I turned on the hazard lights and they worked fine. I swapped out the two relays and traded places. The turn signals worked as they should and the hazards had the issue. I ordered a new relay yesterday. I am now happy with these things, finally. Here's a link to a properly functioning LED relay.

https://www.amazon.com/CEC-Industrie...29658386&psc=1

[dsraven]

great troubleshooting. I figured you had a lighting ground issue and possibly a messed up flasher. good you got it going again.

[Rickysnickers]

Yes, and thank you everyone for all the contributions and suggestions.

[mr48chev]

The relay/flasher thing has been the one bone of contention with led turn lights. I found out that the "electronic" flasher sold in the blister pack at the parts house doesn't work all that great at times either.

On ground issues, I'd say a full half of ground issues that I have run into in the past 60 years were because a guy didn't want to scrape a bare spot on his freshly painted what ever.