3rd Brake Light Not Working

Here I am, yet again, posting about a problem I caused instead of actually contributing something to this forum.

Anyways, I decided to install an Anzo LED 3rd brake light. Looks decent enough and should’ve just been plug and play. However, it, of course, does not work. The cargo lamps will come on very dimly and when I press the brake, instead of the red coming on, it just turns off the cargo lights.

The ideas I had were either A) it’s just a lemon or B) I may need a resistor.

That is until tonight, when the plot possibly thickened. I also installed LED brake/running lights, turn signals, and reverse lights. The running lights would act as daytime running lights, I originally thought, as they stay on when I unlock the truck. Tonight, though, I backed up towards the garage door and did not see the light reflecting off the door. I hit the cargo lamp out of curiosity and they turn on then. So when I unlock the truck or open the door, they stay on and turn off with the cargo lamps, as well as when I hit the cargo lamp button.

Also, new flasher relay for the LEDs, so hyper flashing for signals is not an issue. It didn’t make a difference with the brake/3rd brake lights anyways.

The only thing I can think of is that LED brake/running lights are on a constant hot wire, and because the LEDs don’t require as much power to run, that little bit of power running through it goes to the LEDs instead of just not going through. In effect, that doesn’t give 3rd brake light as much power.
But I have no idea what the hell Im talking about and this post is extremely long as it is.

I’d just like to get some possible solutions. Everything worked perfectly fine before the swaps, too.

 

I have no specific ideas what could cause those problems, but I’d try going back to stock bulbs and then trying each replacement one at a time, like maybe put all halogen back in the tail lights and see if the third brake/cargo light works right.
Do the reverse lights and turn signals work properly? If they’re okay maybe leave those LEDs in, but since the tail light/brake are the same circuit as the third brake and cargo light try those one at a time and see if they work right individually, if they do maybe you’re right about needing a resistor, but I would think at each tail light, not at the third brake light.
Again, all kind of a guess, I’ve never done LEDs with my Tundra, but I’ve chased down similar problems on other rides.

 

Tried doing that last night. The LEDs in the brake nights won’t run with the cargo lamps with the stock 3rd brake lights. With both stock and LEDs in the brakes with the stock 3rd light, the cargo lamps work fine but not the 3rd brake. Tried a couple different bulbs up there, but a halogen wouldn’t work no matter the combination. However, I put an LED in the 3rd housing and it everything works perfectly fine with that. Maybe I just got a bad 3rd brake light from Anzo.

All other LEDs, both interior and exterior, work fine. I’m sending the Anzo light back and, if it is exchanged and still get the same things, I’ll try to figure out how to put a resistor in on the brake lights to see if that does it.

 

What happens if you replace the LED's back with halogen bulbs? Does everything seem to work fine then? Get yourself an ohm meter and check each connection. My assumption would be that running LED's everywhere is causing an issue since they don't require as much power to run them. I'd also take a test light to the third brake light connector to see what you get there as well.

 

That’s what I did. With it all back to halogen, stock 3rd wouldn’t work but stock cargo lamps were fine. Pretty much everything except 3rd worked fine. LEDs in the regular brakes/running did the same thing. When I put an LED bulb in place of the stock bulb for the 3rd, everything worked perfectly fine. The Anzo 3rd lights/housing did not work no matter what, however.

 

Take a test light to the connection and check fuses.

 

Fuses are good. Will post an update whenever I get around to test light. It’s working good at the moment, with LED 3rd, halogen cargos, and LED brakes, at least.

 

Just did all of mine, in and out. Talk to Linda at super Brite LEDs. Tons of knowledge and the best bulbs and needed load resistors to get things perfect. Had tried some crap from Amazon, but most of it wasn't correct. Linda walked me right through it. it's awesome when everything works correctly.

 

Hey, trying to see if you resolved this ? Did you exchange for a new one? Or just an all around different set up? Just got the same part and it did the same exact thing to me

 

I’m guessing we should stick with OEM for our 3rd Brake Lights. Higher quality LED’s work fine in the Original Assy. I’m using Zevo Sylvanias in mine.

 

Aftermarket is prone to cab leaks and failures with non-servicable led boards.

Oem has brand new water proof gasket, and serviceable bulbs to be replaced as needed.

Not a job I'd want to do again, but very glad I did as old cab seal was gunky, and in need of cleaning.

 

You guys are slacking.