My buddy picked up a 98 Blazer today. When we checked it out, we forgot to check the lights. After we left with the truck, I noticed only his 3rd brake light was working. We tried bulbs and they still didn't work. We checked the fuses, they were good. We checked for power at the light sockets, no power. We replaced the brake light switch, didn't fix it. We're not really sure where to go from here. The turn signals, and parking lights all work as they should. Any helpful info would be great!! Thanks.

 

ignition switch-if you had one you could temporarily plug it in under the dash and see-unfortunately if you bought it it's yours but I believe this to be your issue. jp

 

Also check to see if it has a trailer harness, could be a bad connection

 

I would say it's either what is mentioned above or you might check your wiring.

 

try this it worked for me........have someone put there foot on brake pedal jiggle the turn signal seems they get dirty at contac 3rd brake will work when this one dosnt give it a try could be ur problem also dosnt cost anything to try it

 

This is most commonly caused by a problem inside the multifunction switch. Typically, if the giggling method works, the results will be short lived. The problem may be able to be solved by simply replacing the hazard switch (search for "hazard+switch" for further information) to the tune of $15-$20. If that doesn't work, then the entire multifunction switch needs to be replaced.

Some people have tried to disassemble the multifunction switch, but few have actually been able to get all of the springs, latches, etc back together properly to even assess whether their time was well spent.

 

I wasnt saying this jiggleing is the fix .I was saying try this to see if this is where you need to start looking for the fix .It was for me thanks to someone else who said try it and it was the problem I got another turn signal assemby and it being new fixed it........

 

I actually had this problem about a year ago. Brake lights were working fine until one day I came upon an accident and turned on my hazards for cautioning vehicles behind me. Later that same day, a guy caught up to me and let me know my brake lights weren't working. I got home and was puzzled after replacing the bulbs and still no brake lights. I started nosing around up by the steering wheel and remembered using the hazards earlier. I clicked the hazards on and off several times and have had all of my brake lights back ever since.

 

I had similar issues with both my 01 blazer and my 2000 S-10. The blazer had the third brake light working but no left and right brake lights and the S-10 had both left and right brake lights staying on continuously but the third brake light worked properly just like the blazer.

The problem for both ended up being CHMSL relay. One of them sticking closed and the other not engaging. One would think that since this relay is supposed to control the third brake light that it would be that light that would malfunction but I guess this is not the case on these trucks.

on the 00-01 it is the same relay type as both the horn and the fog lamps so it is easy to flip them around to test to see if that is what is wrong.

 

I joined this forum just so I could post this.

This problem has a recall history.

Hope this link works or just Google 2002 Blazer recall.
A girl at work has this problem (only the cyclops works).
This may not be a solution but is worth looking into.
Happy motoring, all.
http://www.motortrend.com/cars/2002/...lls/index.html