Front LED turn signal bulbs make brake lights inop

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Rocket Man

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I've searched and can't find an answer to this. I have all led's in my Denali exterior and interior except the front turn signals. Every single led I've tried in the front turn signals cause my brake lights to stop working when the head lights or park lights are on. Except for the 3rd (high mounted) brake light -it keeps working. I have tried the CK and non CK varieties as well as switchbacks which are advertised to work for ck and non ck applications. Do I need load resistors for the fronts and if so, between a ground and which other wire? I have resistors on the rear turn signals so my cruise works and an electronic flasher module because as soon as I added the front led's I got hyper flash again.
 
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Rocket Man

Rocket Man

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I ended up installing load resistors between the ground and the turn signal + at the front turn signals. At first, I didn't see how the front marker or turn signals would have anything to do with the brake lights but after looking at wiring diagrams, I saw the brake light wire is present at the front turn signals, which I guess makes sense because I believe that in the rear lights, the turn signal interrupts the brake light power. Anyway, I'm thinking that the LED turn signal caused the computer to see an open although I don't see why that makes it eliminate the brake light. I do know that as I installed an LED on one side up front, the brake light on that side would go out in the back. All fixed now. I have noticed while searching back through the forum that there have been several people asking about both brake lights being out but the 3rd high-mounted one still worked, just like my problem.
 

Shadow711

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I just installed leds in the turns like 5 mins ago. Had the hyper flash, didn't check to see if the brakes worked. Put in 2 resistors and hyperflash went away... I am having a problem with leds in the DRL though. I can't get them to turn on. I had pulled both bulbs in the drl a while ago because 1 was burnt out and didnt bother to replace them because i knew i would be switching to leds. I tested the leds in the turn signal socket and they work fine. I put them in the DRL socket and put the vehicle in drive and went to see if they were on but nothing. Checked the fuse and its good. Idk whats up.... Did you have any problems when you switched yours to LEDS?
 
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Rocket Man

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As long as they're installed in the correct polarity they should be fine. Remember, with LED's there's a positive and a negative. Try turning them around in the sockets if you haven't already. If that doesn't have any effect, try regular bulbs to see if you're getting power there.
 

Shadow711

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Yeah I tried that. Regular bulb didn't work either. Just about when I gave up, I unlocked the car and they lit up. So I know they work. They work during unlock, but not when driving? Not sure why
 

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