On my 2003 Blazer 2 door w/4WD, I have no brake lights and have determed that it is a faulty brake light switch or stop light switch as some call it. I am going to replace the switch myself and am looking for a good step x step instructions. Can someone link me to a good write up on this. I have replaced both the bulbs on both sides. The chmsl or 3rd light is not working either. I understand I need to remove the lower plastic kick panel to get to it. Anything else need to come off? I have seen writeups on the full size pick ups and SUV's that say the steering wheel has to be dropped! I hope that isn't the case on the Blazer. I have no FSM and have lost my Haynes. Thanks in advance for your help. Jim

 

I forgot to say I wanted to check the fuses for the Brake Light Switch. I know of two fuse boxes: one is on the driver's side of the dash and the second is under the hood , also on the driver's side. This is actually a Relay and fuse box. Are there any other fuse boxes for this 2003 2 dr.? Can you give me the fuse no. and the criptic description? I sometimes have trouble figuring out GM's abreviations. thanks, Jim

 

Anybody have a good write up, vid on Youtube, or thread on S-10 , etc, on this topic? Even 1AAuto parts doesn't have a video on this project. Thanks, Jim

 

There isn't much to it. You might need to remove the lower hush panel under the steering column to see it, but once you get that out of the way, it is as simple as disconnecting the electrical connector, removing a spring clip, then pulling it off the pin on the pedal assembly.

 

Thanks for the info. I can't drive the Blazer without brake lights. I am wanting to get it back into action.

 

While not impossible, it is not typical for the brake light switch itself to go bad. More often than not, it is a problem with the multifunction (turn, hazard, wiper) switch in the column since the turn & brake functions work using the same bulb filament at the taillight.

Try fiddling with the hazard switch to see if it allows the brake lights to come on.

 

I had read the Hazard switch could be the problem, so I did try wiggling the Haz. switch with the brake pedal pressed down. No brake lights came on. I also read there was a $20.00 Hazard switch replacement so you don't have to replace the entire Multifunction and hazard assembly. Anyway, I hope this Brake Light Switch replacement does the trick. The weather with the cold snap and high winds is not cooperating. It was 26* this morning! Cold for us. Is there any adjustment of the switch after replacement?

 

On my 2003 Blazer 2 door, I have no brake lights on both left and right side. I have no 3rd light either. From my searches on this forum, that indicated a defective 'brake light switch' which I did replace. No change. Still no brake or third lights.
So here's a summary of what I have done so far. It's not the bulbs. I checked them and they were good. I even replaced them on one side just to verify it wasn't the bulbs. It isn't the fuses. Checked them again. There is a fuse panel at the left end of the dash and a 'fuse and relay panel' under the hood. I replaced the 'brake light switch' which is mounted on the top of the brake pedal. Still no brake lights. The tail light and the brake lights are together in a dual element bulb and socket and the tail lights ---all four-- work and the brake lights--- all four---- do not! BTW I did NOT check the relays under the hood.
Is there anything else I should check? If the CHMSL or 3rd brake light fails, does that cause the brake lights to fail on both sides as well? I see some years of Blazers had a tail light/ brake light circuit board mounted on each side for the tail /brake lights. My 2003 doesn't have that item. My parts books confirm this. Is that correct? What am I missing?

 

I did install a new BWD/ Borgwarner switch. It was about 9.00 at Advance Auto. Not a fun job with the severe space restrictions. Tests after the install showed it wasn't the problem. No brake lights on either side. So I am back to the starting point. Can the failure of the 3rd light on the roof cause this problem of no brake lights? What's the next step? What to test next?

 

I am the OP and just wanted to update with some info I left out of the first post. I have no Owner's Manual, no FSM, and I had and misplaced the Hayne's manual. I have no DTC showing.
I mentioned the two fuse panels I know about. Can anyone point out which of the items on the two panels are related to the brake light operation? I have read both and the only one I see that is even close is ABS. Thanks for the info! Jim