LEDs, Resistors, Flashers - Should I just give up?

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A97obs

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I thought we needed another thread on LEDs. I think I've read all of them on this forum, YouTube, and the whole Internet. Everything almost works, but not quite: the side markers aren't working right.

The problem:
When the parking and/or headlights are turned off:
- with the key in the run position, the turn signals and hazards are not visibly operating on the side marker lamps but fine on all other lamps
- with the key in the off position, the hazards are very dim on the side marker lamps but fine on all other lamps. See here:

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The facts:
I do not have a hyper-flash problem.
Electronic, no-load LED flashers were installed for the turn signals and the hazards.
Ground attachments G101, G104, and G105 (the parking and side marker lamp circuit grounds) have all been cleaned and sanded. (They were already very clean.)
All interior and exterior lights other than the headlights have been replaced with LEDs (switchbacks in the four parking lamps) including the dash which of course includes the turn signal/hazard indicators.
Everything works perfectly with incandescent bulbs.
Everything works perfectly when the parking lights and/or headlights are on.
Everything works perfectly if just one LED switchback (in any position) is changed back to an incandescent.
I have tried numerous flashers and switchbacks.

I added resistors. Nothing changed.

What's the problem with the side marker lamps?

Additional information:
I noticed the wires going into one of the parking lamp sockets has been tapped in to. The wires are exposed in a small area.
I sometimes have to turn one of the switchbacks back/counter-clockwise to get it to light, just a millimeter or so after installing it.
One of the side marker lamp sockets seems to have a temperamental connection and I have to adjust/wiggle the bulb to get it to light.
The two issues above are not persistent or consistent.

GIFs of hazards with lights on and off:
Lights on:
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Lights off:
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Note the switchbacks flash a bit brighter when the lights are turned on.
Might you have insight on my issue with my post .
I have perfect working rear tail and front parking LEDs
I added a set of the LED corner side markers that direct plug into the 194 socket and I get a solid light on all the corners and front parking lenses with the headlight switch turned on.
If I shut the headlight switch off the corner LEDs blink with the parking lamps . Soon as I turn on parking lights or all the way to lights On”
All the lights up front light up solid “Zero” indication of blinking.
I tried to flip the led marker plug in for polarity still solid Lit .
I know the LEDs work cause they blink fine with the headlights switch left (Off)
 

Lance 1992

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Might you have insight on my issue with my post .
I have perfect working rear tail and front parking LEDs
I added a set of the LED corner side markers that direct plug into the 194 socket and I get a solid light on all the corners and front parking lenses with the headlight switch turned on.
If I shut the headlight switch off the corner LEDs blink with the parking lamps . Soon as I turn on parking lights or all the way to lights On”
All the lights up front light up solid “Zero” indication of blinking.
I tried to flip the led marker plug in for polarity still solid Lit .
I know the LEDs work cause they blink fine with the headlights switch left (Off)
I'll jump over to your thread and see if I have any insight.
 

Lance 1992

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That's good you figured it out. If you have any comments to add to post #3 in this thread, please do. It sounds like the very first sentence of post #3 is what you did to solve the problem. Annoying how these circuits are wired in my opinion. Enjoy your LEDs!
 

jinks67

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I just did all the exterior lights on my '92. Swapped the flasher relay for one that works with LEDs and everything worked out great ... until I got to the corner marker bulbs. They would work fine with the running lights off but all the lights would go solid as soon as you put the running lights on. After looking at the wiring diagram you can see the corner markers don't actually have a ground and instead are fed from BRN (running or park lights) and the turn signal wire for their respective side. They're getting their ground through the front facing bulbs and it won't work properly with LEDs.

I decided against trying to use resistors and instead used relays to simulate the desired behavior. Might be a bit silly and overkill (need a pair of SPDT relays for EACH side and also ran a separate fused 12v to the front) but this does simulate the normal operation perfectly, regardless of bulb type. Thought I'd share in case anyone else has an aversion to installing resistors like I did, or is having difficulty otherwise.

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I wouldn't recommend trying it unless you're comfortable with electronics. Also in my case there is an audible clicking from the engine bay when the turn signal is engaged that you can hear if you're standing near it. It's subtle enough that I don't mind it but louder relays might be annoying.
 
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AK49BWL

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I'll never understand the aversion to resistors. They're on the blinking light circuit, so the notion that they're going to overheat and cause a fire is pretty well laughable at best, especially if you mount them properly to a metal base where they can further spread their negligible heat generation.
 

jinks67

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I'll never understand the aversion to resistors. They're on the blinking light circuit, so the notion that they're going to overheat and cause a fire is pretty well laughable at best, especially if you mount them properly to a metal base where they can further spread their negligible heat generation.
I wasn't worried about heat. It had more to do with OCD in my case :)

I'm an industrial electrician by trade, I didn't like the idea of getting around the problem with a resistor. The relays, fuse holder and wire were relatively cheap with the main benefit of the circuit behaving the same way no matter the characteristics of any bulbs that get thrown into the mix. Downsides are altering stock wiring and the extra time involved - which obviously isn't going to be for everyone.

Not saying anyone should do it this way, simply want to provide another way to skin the cat in case anyone is looking for one, for whatever reason.
 
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