LED upgrade (headlights and taillights) question

[Cole]

I just upgraded all my exterior lights to LED's (except the side markers) and everything went smoothly until the driver's side parking light. When I put that LED light in it all went haywire. Of note - I don't have the LED relay but I will be purchasing today, instead I cut the circuit in the existing relay as shown in other posts and Stu's site. (https://www.stu-offroad.com/electrical/led1/led-3.htm)

Anyway, after I put the driver's side LED in the blinkers would work, at a normal speed, with my lights off, but the entire dash would turn on and off with the blinkers. When I turned on my lights the blinkers wouldn't work at all and the left blinkers light on the dash would stay light.

Any thoughts? Comments? Suggestions? I guess I didn't try to flip around the LED, is it possible I had it plugged in so the polarities were reversed? Not sure if that matters with LED's..

 

[02SteelBlue]

Not sure, but I think LEDs wont come on if they're put in backwards.

 

[oldjeepman]

I changed all my light also and installed the led flasher relay, they all work maybe they might flash fast I don't know or worry about it. They Work..

 

[Cole]

I thought I read somewhere the polarity can get messed up.. that or I have a bad ground maybe.

 

[Steel City 06]

It’s likely that the sidemarker bulb is causing issues. The sidemarker bulb grounds through the inactive filament in the fender bulb. Remove the sidemarker bulb and see if the problems persist. I replaced all of the turn signal/taillight/sidemarkers with LEDs. To convert the sidemarker, you’ll need to convert it to a three wire setup that doesn’t ground through the fender bulb.

 

[Steel City 06]

On page 5 of this thread I posted a crappy wiring diagram on how to wire in the sidemarker bulb. There is also a way to do it with a load resistor instead of a dimming resistor, but that defeats the point of LEDs.

https://wranglertjforum.com/threads...h-leds.9149/page-5#lg=attachment82712&slide=0
Besides the splices in the picture, no other wiring changes are necessary. You only need to insert the correct LED flasher relay in place of the stock one.

 

[Cole]

Good point, although I didn't replace the side markers .....

 

[Steel City 06]

Try pulling the halogen sidemarker bulbs out of the sockets and see if the fender bulbs still act funny. They can still cause issues with the fender bulbs.

The current that flows through the halogen sidemarker bulbs is not enough to light the inactive filament on the halogen fender bulb, but is more than enough to light the other “filament” on the LED bulb, causing the fender bulb to be at the incorrect brightness and for the sidemarker to either be very dim or not visible at all.

 

[Steel City 06]

Also I do recommend flipping the LED bulbs around if they don’t light at all. Cheaper LEDs do not have correcting circuitry to reverse the flow of electricity when inserted backwards. The individual light emitting diodes on the bulbs will not light unless the current is flowing in the correct direction. In fact, they don’t allow any current to pass whatsoever (LEDs are a special type of diode).

Inserting the bulbs backwards will cause no damage. They simply won’t turn on.

I also had an issue where the sockets for the fender bulbs themselves were worn out. I replaced both of them. The parts were available on rockauto and amazon.

 

[Cole]

I'll investigate today by taking out the side markers halogen bulb. Seems to work fine but we'll see.

Also. I did flip the LED. No luck. Way too easy. And it's just the driver's side that has an issue. Everything works until the LED is put in the turn signal. Odd.

 

[Cole]

So. I took out the side marker halogen bulb and everything works as it should work with LEDs all around. If I put back in the halogen side marker it goes wacky.

My passenger side marker is also out.

Is this something a LED flasher relay would fix or is this a grounding issue?? Right now I did just cut the circuit on the stock flasher relay.

 

[Steel City 06]

You'll need to convert the side marker bulb into a three wire (independently grounded) setup. The crappy wiring diagram I linked above shows how to do it with an LED side marker. I recommend purchasing a 1 watt resistor kit so you can fine tune the low brightness of the sidemarker.
With the work involved, I recommend going ahead and purchasing LED bulbs for the side markers. The work to get the halogens to work in that location is the same, bit it will require a different higher wattage resistor that would be incompatible with an LED bulb. Best to do it once.

 

[Steel City 06]

An LED flasher is recommended. Later models use the Novita LM470. You should be able to buy it at any auto parts store. Early models use the EP26 flasher.

 

[05pf13]

So, I have a problem with the side marker signal lights. I already replaced the rear and front lights to LED and the flasher to low voltage. The front marker lights do work correctly, but the side marker lights only light and do not flash like before, they go dead. As it was I had to replace all four front bulbs (front park and side marker) before all lit correctly. Not sure why they don't blink like before but they do light steady when in park light mode or headlight mode. I can live with the way they work , but if anyone has any input on why this is happening I would appreciate it.
Let me note that the front LED bulbs for the parking lights are what they call "switchback", which are LED's that are white when turned on but turn amber when being used as a signal light, then back to white. They do work properly, but only after replacing side marker lights to LED. Before I replaced the side marker bulbs the front did not work right and my dash lights were going haywire.

 

[Steel City 06]

So, I have a problem with the side marker signal lights. I already replaced the rear and front lights to LED and the flasher to low voltage. The front marker lights do work correctly, but the side marker lights only light and do not flash like before, they go dead. As it was I had to replace all four front bulbs (front park and side marker) before all lit correctly. Not sure why they don't blink like before but they do light steady when in park light mode or headlight mode. I can live with the way they work , but if anyone has any input on why this is happening I would appreciate it.
Let me note that the front LED bulbs for the parking lights are what they call "switchback", which are LED's that are white when turned on but turn amber when being used as a signal light, then back to white. They do work properly, but only after replacing side marker lights to LED. Before I replaced the side marker bulbs the front did not work right and my dash lights were going haywire.

Did you convert the sidemarker lights to three-wire? The fender/sidemarker LEDs are not plug and play. The sidemarker bulbs ground through the unused fender turn signal filament. Since the LEDs use different current, they won’t light correctly.

I linked a wiring diagram in one of my posts above in case you haven’t seen how to do it before

 

[Chris]

So, I have a problem with the side marker signal lights. I already replaced the rear and front lights to LED and the flasher to low voltage. The front marker lights do work correctly, but the side marker lights only light and do not flash like before, they go dead. As it was I had to replace all four front bulbs (front park and side marker) before all lit correctly. Not sure why they don't blink like before but they do light steady when in park light mode or headlight mode. I can live with the way they work , but if anyone has any input on why this is happening I would appreciate it.
Let me note that the front LED bulbs for the parking lights are what they call "switchback", which are LED's that are white when turned on but turn amber when being used as a signal light, then back to white. They do work properly, but only after replacing side marker lights to LED. Before I replaced the side marker bulbs the front did not work right and my dash lights were going haywire.

Put the side marker bulbs back to incandescent bulbs. They use floating grounds, and you will have nothing but problems with LEDs in those things, trust me.

 

[Viking Jeeper]

I replaced one side marker bulb with an LED with no problems. Never heard of that type of ground.

 

[Moab]

Put the side marker bulbs back to incandescent bulbs. They use floating grounds, and you will have nothing but problems with LEDs in those things, trust me.

Might replacing the relay keep him from having to rewire the side markers too?

 

[Chris]

Might replacing the relay keep him from having to rewire the side markers too?

Well yes, you need a LED flasher relay to run LED taillights and turn signals.

However, that relay won't do anything about the fender flare side markers (assuming there is LED bulbs in those). Those are the ones with the floating ground. While there is a way around it, you have to be good with electrical stuff, and I'm not, so my solution was simply to remove the LED bulbs from the side markers. Just not worth the hassle IMHO.

 

[Fonz54]

Not sure, but I think LEDs wont come on if they're put in backwards.

Yes they will not work if they are installed with the incorrect polarity.