3rd Brake Light always ON...

[Samusss]

OK- this is weird. My 3rd brake light (the LED one on top of the rear hatch) is always on if my lights are on. It stays dim and gets brighter when the brakes are hit, just like the regualr brake lights. I know for a fact though, that it's only supposed to come on when the brakes are pressed. If I hook my trailer up to my wiring harness, then it acts normal. I've tried replacing the harness and that didn't fix it. I've checked all the fuses. Anyone know what could be causing this? Sometimes it even strobes all on its own.... HELP

Eric

 

[Texan01]

I'm gonna go out on a limb and say that it's a bad ground. Or could be a bad switch.

Or could be the muffler bearings, or the fuel radiator, might be the air in the tires needs to be rotated

 

[Lifted95X]

Ive heard this happen when your water pump filter gets dirty. But it could also mean that your exhaust fluid is low.

 

[Henry]

I'd really be suspicious of the trailer wiring and harness, either a bad ground or a short would be what I'd look for first.

Oh, and have you noticed all the funny people we have on this site?

 

[mike dilbone]

i had a chevy that did the same thing.sometimes the 3rd brake light would blink with the turn signals too.
the dealer replaced the turn signal switch and that fixed it.as it turns out something was wrong in the hazard light part of the switch.

 

[Lifted95X]

Originally posted by mike dilbone
i had a chevy that did the same thing.sometimes the 3rd brake light would blink with the turn signals too.
the dealer replaced the turn signal switch and that fixed it.as it turns out something was wrong in the hazard light part of the switch.

I totally forgot about that...if the air in the hazard switch gets low...that can cause that.

Sorry....last one

 

[mike dilbone]

everyone knows there is no hazard switch air.
they use hydraulic fluid.

 

[Samusss]

figures...

figures the first time i run into a probelm i can't solve, i get a bunch of comedic response! hehe. anyways- here's my update- i changed my muffler bearing, filled my trun signal hydraulic fluids and rotated my tires. it's still broken. as far as checking the ground, where are the connections for the 3rd brake light located? where should i check the wiring? thanks.

eric

 

[Texan01]

Honestly, I don't know where the grounds are on the Explorer. I'd pull the light out (if possible) and ground it and see if it goes away, if it does, then you got a bad ground for sure. My guess on the grounds is probably on the frame or body where the trailer harness plug is.