Third Brake Light replaced but not working Revisited….

So when you say doesn't work is it should what is actually happening back there or can you see Is there garage door or something you can pull up against does the light come on sometimes Is it intermittent like a failed ground when you say you replaced that lamp how did that go I have one laying out on a spoiler right now on the trunk of a car I think I took the third light out and the wires run down and go down a corner of the spoiler and into the hatch area under that black plastic panel with the hand grip to pull it down or whatever that's for so maybe there's an intermittent ground or something like that All of the brake lights on the car LED if I'm not mistaken so adding one more LED or the three that go in that third brake light shouldn't cause too much of a commotion but isn't that the way it's kind of wired anyway I'll have to go look when the sun comes up but I have a hatch completely open right now and everything clearly visible so I'll try and take a look at how this could go intermittent so in other words if you give the third eye brake light in your car right now straight 12 volts or even use a 9 volt battery for the two terminals does it light up consistently the third eye brake light in the spoiler while you have the hatch half up and you're sitting there with the two wires touching the 9 volt moving it away touching it again does it consistently light up? Then it would seem your problem maybe what the body control module or something along those lines a loose ground behind that black panel aren't there a few in Massachusetts when I live there grounds would get very rusted. Grounds good actually get separated from the body of the car pretty easily in that weather when when I live there anyway they had to be checked pretty regularly but this was many years before 21 computers in a car and or the Prius was even a thing.

 

No problems with your idea. The stop lights in the body are wired in parallel to the center mount stop light. All 3 get power (blue wire) from the stop light switch. They have different grounds (white wire with black trace).

I might want to look at the wiring for the tailgate where it flexes up near the hinges. It can break there after bending hundreds of times over the years.

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Yes right up there under the headliner That's a good call I didn't know those things flex that bad of course I haven't had any problems with my brake lights or anything like that but usually I'm looking at those grounds back there especially if I'm in a state like Western Massachusetts we're funny business and rain and rust is a known problem.

 

Yeah no issues with that I'm just trying to figure out how you're not getting power to the third brake light through the normal channels of the normal wiring that's provided in the car? Is this thing completely separated and the body control module lights it up as a third party light that has nothing to do with the rest of the brakes? Don't know the way you solved it just like connecting up the power that runs through my receiver to my trailer absolutely personally I would just like to figure out why I have to do this which I haven't so we haven't got there yet and no pulling out tons of wiring diagrams is not going to be a thing for me because other people who specialty that is should be able to come along and well make it all better.