Led bulb headlight

[Patt]

Hi guys,

I have installed LED in my headlight on my 1994 sierra k1500. It seem that since my daylight (running light) doesnt work. What is the problem? Do resistor will fix the problem?

 

[herkyhawki]

LED bulbs have limited hours of operation at full lumens, some are only like 200 hour range. This might mean you are better off NOT having the DRL's, as that woulsd power the bulbs for lots more hours.

 

[tpass]

Doesn't the DRL circuit go through a diode or resistor so the headlight isnt at full output? The LED bulb probably doesn't like the voltage it's getting.

 

[thinger2]

A few years ago a customer who is the absolute king of semi "Chicken Lights"
tried to install LEDs on a 96 Freightliner.
Sometimes one low beam would work and not the other one, if you hit the high beams one would sometimes work but not always etc...
After about two days of messing around with this thing it came down to two problems.
1) The factory headlight pigtail has a diode for each light that keeps power from backfeeding. He didnt know what the little rounds things were so he cut them out.
2) Bad grounds. this thing was a farm truck and had about 950k on it and just about all of the grounds were bad.
Between the money he spent on cheap chinese chicken lights and our bill for 80 man hours to rewire the thing it was more than the truck was worth.
LEDs are very ground sensitive and path sensitive.

 

[df2x4]

You didn't mention what the exact problem is, but no LED headlight is going to work properly with the factory DRL setup in these trucks. They should still illuminate, but as tpass mentioned the factory DRL setup passes through a diode/resistor pack and uses either reduced voltage or PWM (not entirely sure which) to limit the output of the standard halogen 9006 bulb. LEDs are not nearly as sensitive to operating voltage and will run at full brightness even when the DRLs are active.

If you want functional factory DRLs that dim as they should, running LEDs is not an option. They'll just run at full brightness all the time.

 

[Caman96]

Unless the LED’s are in different housings, I can’t imagine the lights are working that great themselves.

 

[Patt]

Okay! I understand the low voltage and that the LED cannot handle that. But can I bypass the DRL factory setup to my parking light instead? I just want something that light up automaticly like the DRL is suppose to do with the 9006 headlignt bulb. I dont matter if it is the parking light as the DRL light.

Or, worst case, I dont mind if the LED buld in the headlight is fully on as DRL....

 

[kennythewelder]

Okay! I understand the low voltage and that the LED cannot handle that. But can I bypass the DRL factory setup to my parking light instead? I just want something that light up automaticly like the DRL is suppose to do with the 9006 headlignt bulb. I dont matter if it is the parking light as the DRL light.

Or, worst case, I dont mind if the LED buld in the headlight is fully on as DRL....

Yes, it can be done. I just pulled the fuse for the DRL module, so that my LEDs would not come on without turning the headlight switch. You are going to need to trace out the out out power wire, on the DRL module, cut that, and tie into it with what ever lights you want to now be your new DRLs. IDK just exactly where that wire ties into the head light harness, but that maybe where you could make your tie in, for you new DRLs.

 

[df2x4]

Or, worst case, I dont mind if the LED buld in the headlight is fully on as DRL....

They should be already. If they don't light up at all when the DRLs are active then something else in the DRL system has failed. Make sure your DRL fuse isn't blown.