TJ LED front turn signals

bcdawson27

bcdawson27

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Indiana
Having some trouble with my turn signal lights after installing LED switchbacks, after swapping the old halogens out the turn signal light on the dash stays on and the lights flash opposite of each other when the hazards are on. just swapped back to the halogens for now but would love to get my LED’s back in it
 
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It's not the flasher causing the problem, it's the fact the TJ's turn signals and side marker circuits were designed with conventional incandescent bulbs in mind. Incandescent bulbs conduct equally in both directions, LED bulbs only conduct in one direction so they disrupt circuits that depend on the bulbs being able to conduct in both directions. Like the current flow through them reverses when the headlights are turned on.

Personally I only run LED headlights and tail lights without problem. My side markers are LED and they don't work right when my headlights are on. I so seldom drive my TJ at night that I never bothered to alter their circuit with a rectifier to fix the problem.

Essentially I'm saying that LED bulbs won't always work right in our TJs, don't expect them to.
 
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Jerry Bransford said:
It's not the flasher causing the problem, it's the fact the TJ's turn signals and side marker circuits were designed with conventional incandescent bulbs in mind. Incandescent bulbs conduct equally in both directions, LED bulbs only conduct in one direction so they disrupt circuits that depend on the bulbs being able to conduct in both directions. Like the current flow through them reverses when the headlights are turned on.

Personally I only run LED headlights and tail lights without problem. My side markers are LED and they don't work right when my headlights are on. I so seldom drive my TJ at night that I never bothered to alter their circuit with a rectifier to fix the problem.

Essentially I'm saying that LED bulbs won't always work right in our TJs, don't expect them to.
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It's so easy to make any LED, nonpolar or polar, work on the TJ front side marker and parking lamp locations using 4 diodes and 2 resistors. I can do it in about 30 minutes and it can all be hidden completely in the loom easily.
 
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machoheadgames said:
It's so easy to make any LED, nonpolar or polar, work on the TJ front side marker and parking lamp locations using 4diodes and 2 relays. I can do it in about 30 minutes and it can all be hidden completely in the loom easily.
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It's only "so easy" for those who know electric/electronic circuits. And with a bridge rectifier, the same as four diodes, no relay is needed.
 
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There's a diagram floating around making it super simple....as long as someone can handle a decent crimper and some butt splices, it's really easy.

Relay/flasher is still needed for blinking the LEDs.

You can skip the resistors if you use the rectifiers, but you get alternate blinking. Which is fine if happy with it. I personally like what the resistor/diode mod does better, it operates the side marker bulbs at two stages of brightness. Looks like a 3 wire bulb, which is really sharp looking to me. It also runs them at an artificially dimmed down brightness for the parking lamp so that you can utilize a bright LED for turn signaling and keep it not too bright on running lamp mode.
 
machoheadgames said:
There's a diagram floating around making it super simple....as long as someone can handle a decent crimper and some butt splices, it's really easy.
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The average guy without some amount of electrical education is not likely to be able to do that modification. Diagrams are easy for someone who understands wiring, not so much for those who don't.

And installing a bridge rectifier for each bulb in the circuit means they'll operate normally without the need for relays or resistors.
 
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Jerry Bransford said:
The average guy without some amount of electrical education is not likely to be able to do that modification. Diagrams are easy for someone who understands wiring, not so much for those who don't.

And installing a bridge rectifier for each bulb in the circuit means they'll operate normally without the need for relays or resistors.
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If they can't follow this diagram, then they probably shouldn't be touching their wiring at all, including adding rectifiers, and should probably stick to incandescent bulbs.

I don't see how a rectifier fixes the flasher relay issue. The LED is still very small load and the stock flasher wants to see the load of a normal bulb. If they have changed their tail lamps to LED already then yes, they are good to go, but for anyone just changing the front markers out they should need the LED flasher.

I understand how the rectifier works. As I said though, I like to use a bright LED so that it's bright for turn signals and not bright (dimmed via the resistor) as a running lamp. If you use the rectifier method, you are stuck at one level of brightness that is comfortable as a running light and not all that bright for turn signaling, or vice versa.

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machoheadgames said:
Yes, that is the only relay I ever talked about and that was the only purpose I mentioned it for.
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Ok, I got confused when you said two relays.

"It's so easy to make any LED, nonpolar or polar, work on the TJ front side marker and parking lamp locations using 4diodes and 2 relays."
 
Jerry Bransford said:
Ok, I got confused when you said two relays.

It's so easy to make any LED, nonpolar or polar, work on the TJ front side marker and parking lamp locations using 4diodes and 2 relays.
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My bad, I screwed that one up. I meant resistors. 2 resistors, 4 diodes, and 1 flasher relay total is all I do to fix up LEDs my way completely.
 
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And with that much effort needed, the real question is "Why bother switching to LED bulbs in the turn signals anyway?"

BTW, I'm an Applications Engineer for an LED lighting manufacturer, and even I don't bother adding LEDs in turn signals except for on the Harley, and I bought plug & Play lights for that.
 
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WestCoastDan said:
And with that much effort needed, the real question is "Why bother switching to LED bulbs in the turn signals anyway?"

BTW, I'm an Applications Engineer for an LED lighting manufacturer, and even I don't bother adding LEDs in turn signals except for on the Harley, and I bought plug & Play lights for that.
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30 minutes of work and like $10 of parts. To each their own but to me it’s fully worth it.
 
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