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LED rear light won't light

2K views 10 replies 3 participants last post by  boggincj7 
#1 ·
OK, so I just installed rear LED's and the blinkers work fine. But when I turn on my headlighrts they won't blink anymore. Also my rear brake lights won't light up when you hit the brake pedal. When you press the pedal I get no power on the wire, but when you turn on the lights they will work but won't blink and no brake light. I'm outta idea's any help would be appreciated.
 
#2 ·
Is there a difference between having the lights on or off with the brake light or does the brake light not work at all under any condition?

How do you have them wired? LED won't show the same symptoms if you have a bad ground. it just won't work.

It almost sounds as if you have something miss wired. If you have the headlights and the TS wired together. The TS will work until the headlights are turned on. wich explains on problem but the brake and TS are on the same circuit so if one works then the other should also. Only thing in commom it the TS switch.

What lights did you buy and how did you wire them. Give us colors and everthing.
 
#3 ·
Another thing to keep in mind with LED's, you have to have the polarity correct or they won't work.

(Well, the one's we use here for assemblies at work don't anyways.)

But when I turn on my headlighrts they won't blink anymore.
When you turn on your headlights you are also turning on your tail lights. If your tail lights have direct power to the LED, then the flasher relay is useless. I have never wired LED taillights, but I would assume you have a connection for taillights and a seperate connection for Blinker/Brake Lights.

When you press the pedal I get no power on the wire, but when you turn on the lights they will work but won't blink and no brake light. I'm outta idea's any help would be appreciated.
Honestly it sounds like you may want to start from the beginning and follow each wire according to a drawing (or if none exist for your setup, have someone create one for you). I think there are one or more wires in the wrong place. I work with a few guys that could have a drawing for you in 15 minutes, just let me know.

Are you running one LED as your Tail light, blinker, brake light, or are you running like a Red LED and a seperate yellow LED for a flasher?
 
#4 ·
My LED's are light, turn and stop all in one. But I noticed late last night that my brake switch is missing all together. I never noticed a brake light problem before but maybe it's been a problem for awhile. I bought a new switch today so I will try that and see if that's my problem. Thanks for the help so far.
 
#5 ·
So I installed the switch and now my brake lights and blinkers work, until you turn on the headlights. Then the lights light up to full power and my brakes and blinkers won't work. Do I need a resistor in there or something?
 
#6 ·
Do you have the brake and light wires reversed? I'm thinking the LED may havea different way of lighting up the running lights and brake lights if they use the same LED for each function and if you reverse them then the lights come on full and you never see the TS or Brake lights.

Before anyone yells "Grounds", LED don't behave the same way. They just don't work.

The brightest lights should be the TS and Brakes and the dimmer lights should be the running lights
 
#7 ·
Okay, so this is a combination style LED. How many wires are coming out of the back of the LED? 2? I'm hoping you say more than that.

I'm probably stating the obvious, but what it sounds like to me is you have a direct feed from your headlight switch that is overriding all other feeds. If you only have a two wire LED, you're going to have to spend some time up front (meaning behind the dash/fuse block/steering column) wiring this correctly so that your blinker and brake lights override your tail lamps.

It's still pretty early in the morning here, but even with that said I'm still trying to figure out how this would work if you only have a 2 wire LED. I'm starting to think that it won't properly work ever unless you bought a kit that has multiple feeds into one LED - because (assuming again you have 2 wires) if you had your tail lamps/headlights ON (meaning power to the 12V wire and a ground wire) what could you expect to happen when you hit your brakes???? They would just get another connection of 12V, so they would not change. Again with the blinker, if you had tail lamps/headlights ON, when you turn on your blinker it's just spitting 12V again to the wire that already has 12v to it.

Please tell me you have more than 2 wires coming out of that LED?
 
#9 ·
Yeah, definately possible.

I'm just thinking about the problem he has described and it sounds like all power is going to one 12V lead. A lot of the cheapo LED lights I've seen are nothing more than what you said... a red running light.
 
#10 ·
Yes it is just 2 wires and a ground. But no different than stock lights just no reverse lights. Maybe they are crossed, I will have to try that later today, as I'm off to work!! Thanks for the help so far.
 
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