Third Brake Light

[WhoDatPanic]

well i just checked the light again with a 9v and it didnt work this time ??? wtf lol

 

[Rivieraracing]

Make sure you are doing the positive end on the correct side of the plug, otherwise get a fresh 9v and try again, or better yet just hook it up to the truck battery!!!

 

[024mula]

Well, I dug this old post up..... I too am having a problem with my CHMSL on my 06 YUKON. my problem is paying so much for one that is maybe burnt out. I am going to check the fuse and 9v or 12v battery test it when it returns home. My wife demands to drive it instead of the other car, a 2005 SE-R Altima, she has issue with driving a six speed... Oh Well....


Oh btw, how much was your Blackbear tune....Thinking about this instead of a power programmer type tuner...

 

[STL_Denali]

Bringing up an old thread, but mine went out a while back, bought a new one and it doesn’t work. I’ll will be checking them on a 9v and checking CC this weekend.

 

[Doubeleive]

Apparently there is two fuses for the center high mount 3rd brake light, one under the hood #49 and one by drivers door side panel #12, found out mine wasn't working by just doing a light check in the dark against glass, turns out I had bent the pins last time I re installed my putco after the back glass was broken, go figure.......

 

[Skipper50]

Odd note here.

I thought I would upgrade my brake and reverse lights with LEDs. The devices I used did not have resistors built in so they didn't work.
Irritated me but I switched back to traditional bulbs and all seemed OK.

The following week I had some road work and tried to engage the cruise control with negative results.

Went through all the schematics I could find and found nothing that seemed rational but magically the crusie startedworking on my next road trip.
I didn't realize, until sometime later, that the third brake light was not functional.
I wasn't terribly excited about replacing this or trying to troubleshoot until I remembered that my mechanic told me that this year in Texas, 2018, a inoperable third brake light could result in a traffic stop/ticket.

I had removed the third barke light and determined that it was getting voltage when the brakes were depressed and ordered a replacement light module via Amazon.
I finally got motivated to replace the lamp fixture (new inspection sticker is due in 15 days) and replacement module did not remedy the issue.
Breaking out the voltmeter I foumd the CHMSL fuse is good. My cruise disconnects when braking so I'm thinking that Cruise Control fuses are not an issue.

If anyone has had success with this issue I would like to know what they did to correct the issue.

 

[Doubeleive]

Odd note here.

I thought I would upgrade my brake and reverse lights with LEDs. The devices I used did not have resistors built in so they didn't work.
Irritated me but I switched back to traditional bulbs and all seemed OK.

The following week I had some road work and tried to engage the cruise control with negative results.

Went through all the schematics I could find and found nothing that seemed rational but magically the crusie startedworking on my next road trip.
I didn't realize, until sometime later, that the third brake light was not functional.
I wasn't terribly excited about replacing this or trying to troubleshoot until I remembered that my mechanic told me that this year in Texas, 2018, a inoperable third brake light could result in a traffic stop/ticket.

I had removed the third barke light and determined that it was getting voltage when the brakes were depressed and ordered a replacement light module via Amazon.
I finally got motivated to replace the lamp fixture (new inspection sticker is due in 15 days) and replacement module did not remedy the issue.
Breaking out the voltmeter I foumd the CHMSL fuse is good. My cruise disconnects when braking so I'm thinking that Cruise Control fuses are not an issue.

If anyone has had success with this issue I would like to know what they did to correct the issue.

if the 3rd brake light harness has power when applying the brake pedal then your light is bad or you have bent pins inside the 3rd light housing plug or if the light is led then the polarity is reversed in which case try plugging it in backwards.