Led conversion (running/turn signals)

[squarebodysteve86]

Are you running the led flasher relay with the external ground wire? It will make a difference. I've converted my 87 to all led bulb with original sockets and have not had any problems. If you are running that style relay, it's probably going to be the switchback bulbs giving you the issue.

I've tried several different relays, one I'm currently using has an independent ground, and I've tried standard led (not switchback) 1157

 

[SirRobyn0]

not ready yet for consumption one moment please.

 

[SirRobyn0]

FYI, LEDs are a computer circuit. These trucks were not designed for a circuit with a clean enough connection. Many people have tried them [including me] without success. The slightest resistance they won't work.

I completely agree.

I'm not trying to say that LEDs can't be done or that you someone can't do them and be happy, but I've seen a lot of issues. If a classic comes in the shop with LEDs and has a lighting issue first thing we do is remove the LEDs and go back to incs. Almost always solves the problem.

I'm just putting that out there.

 

[Turbo4whl]

I do appreciate the in depth response but wiring is not my strong suit by any means. So, honestly, it's kind of hard for me to understand. The thing I have a hard time understanding is, I have a video of this exact truck with all these leds working, running lights and turn signals, as it was supposed to. And now for whatever reason, they do not. I know they can work. I've seen it.

Okay, then try this. Remove both 194 side marker lamp bulbs and see if you current feed back problem goes away.

 

[squarebodysteve86]

I completely agree.

I'm not trying to say that LEDs can't be done or that you someone can't do them and be happy, but I've seen a lot of issues. If a classic comes in the shop with LEDs and has a lighting issue first thing we do is remove the LEDs and go back to incs. Almost always solves the problem.

I'm just putting that out there.

Yes. Im with you. The other leds will work if I put incandescent 1157s just in the front signal sockets. I know it can be done. Somehow or another. It's similar to the newer jeeps in a sense. I'm not sure if the signals and running lights break circuit via ground, or how they work. I guess I'm not necessarily asking why my lights aren't working, I'm more asking HOW can I get these leds to work with diodes or resistors. Maybe I'm stubborn, maybe I'm dumb. Either way, I'm set on getting these to work, as I've seen it work, on THIS truck.

 

[squarebodysteve86]

Okay, then try this. Remove both 194 side marker lamp bulbs and see if you current feed back problem goes away.

With leds in the front 1157 sockets, 194 removed, I have .4v at the blue wire (not enought to be a problem). With the 194 led in, I have 11v at the blue wire. 12v at the battery.

 

[Turbo4whl]

@SirRobyn0 Rob your answer sums it all up. 40 year old truck was not made for LED's. You can be sure the truck that @squarebodysteve86 saw with all (these) LED's working fine was re-wired by someone.

 

[squarebodysteve86]

@SirRobyn0 Rob your answer sums it all up. 40 year old truck was not made for LED's. You can be sure the truck that @squarebodysteve86 saw with all (these) LED's working fine was re-wired by someone.

It was my truck, lol

 

[squarebodysteve86]

It was my truck, lol

I'll upload the video to YouTube and share the link. Idk how to share videos on this forum.

 

[squarebodysteve86]

@SirRobyn0 Rob your answer sums it all up. 40 year old truck was not made for LED's. You can be sure the truck that @squarebodysteve86 saw with all (these) LED's working fine was re-wired by someone.

Heres the video of MY truck.

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[Turbo4whl]

Okay it works because the 194 LED bulb has a transistor inside. What is the drawback, you have a current feedback. Like I stated earlier, the transistor will fail and can leak current.

 

[squarebodysteve86]

Okay it works because the 194 LED bulb has a transistor inside. What is the drawback, you have a current feedback. Like I stated earlier, the transistor will fail and can leak current.

So what do you suggest to counter that? I've tried other 194 leds and it's still not quite right

 

[Turbo4whl]

You read my complete expiation of what the front marker light does with an incandescent bulb, current flows both ways to light the bulb?

An LED bulb, light emitting diode, can only flow current one direction, so how can it work? The transistor, a switch, makes it work to flow current each way. What did I say about the transistor? Not made to work and change the current flow so many times, it fails.

You said you were not good with wiring. I gave a simple fix. The only other change (also involves changing the wiring) is to have 2 LED bulbs in the marker lamp. That is the issue, 1157 bulbs are like two lights in one. Use one wire from the original 194 bulb. Wire the other side of the bulb to ground. Second 194 bulb you add to the side marker could the use the other wire feeding the the original 194 bulb to the second new install LED bulb, the other side to ground. This would give you marker light on with the parking lights and another light to blink with the turn signal. This will also prevent the back-feeding current.

The fact remains, in a square body truck, the front side markers are feed with two positive power feeds. One more time LED = light emitting diode. Diode = check valve for electrical flow, only flows current one way.