I have a 2000 Blazer, the top strip brake lights work but the left and right side brake lights do not. the bulbs are fine, the tail lights are ok, and the turn siganls work ok, just the brake lights in the tail light are doa. Also the hazzard light don't work. Any help???

 

it's either a fuse....or the relay that makes the brakes go on and off...when it happened to me..it wasn't until my turnsignals blew that I had realised my brake lights hadn't been working....(the top strip worked) so chances are you will need a new switch...

 

check you wires for third brake light, might have a bad ground or connections...

hazards try pushing the hazard button down and wiggle the turn signal switch to left and right turns if they come on then its ur turn signal switch and have to rip apart your steering column; older gms and the g-vans are really bad at this, which the blazer steering column is exaclty identical, i get these at work sometimes and have to jimmy-rig them most of the time but only have had to replace 3 so far.

but that might not be the problem though, dont worry i hate electrical problems b/c they are a b!tch to find and 90% of the time its something very simple when you do find the problem, thats just what i've had to deal with so far though

 

I have the same problem with my 2001 Blazer. The top brake light works, but the bottom ones, as well as the hazard lights suddenly stopped working. I took it into the dealer, and they got them to work momentarily by jiggling the turn signal switch. They claimed it was a relay switch in the turn signal switch and would need to be replaced to the tune of $250. Does this diagnosis sound correct? If so, is replacement of the relay (and at this cost) the only option. (The turn signals work fine.)

 

If they giggled the turn signal stalk, it's definitely not a relay. There are NO relays in the steering column. Sounds like a snow job so they can get paid twice.

 

Silly question time. Did you check with something like a volt/ohm meter. A test light? On lighting a test light can still be used but I dont recommend it. As far as I know, no relays, unless you decide that any contact is now a relay. In which case the dealer is right cause there are contacts in the turn signal assembly inside the steering column. No electrically operated relays.

So whats causing one to work while other does not?

Engineering is overcooked as in all modern cars. The overhead brake light strip is wired directly and all by itself to the brake switch. At least according to diagrams I have. So the wiring for the other lites is the same as per usual and goes thru the turn signal system, but the top strip comes directly from the brake switch. Be happy that it does cause at least you still have something working, right?

So if you have checked the wiring and the bulbs with a volt/ohm meter and found the battery/12volt, side of the ckt lacking, then it points back to cut wires or bad turn signal contacts. DO NOT FORGET ground side of ckt. Dont forget to check for outputs at the correctly colored leads at the BOTTOM of the steering column. I may be wrong in your particular case, but many GM products have a plug down at the bottom of the steering column, that can be accessed to test the steering column. Factory techs dont like taking it apart for no reason at all either. During assembly the steering column is added after the car wiring and simply plugged in. Hope you can gain access to this plug, makes testing much easier. One side of the plug goes up to the lever, key and emergency switch while the other side of the plug goes to the rest of the car. Remember that the 12 volts to do the operating also gets disconnected and you will have to use the OHM part of the meter to get your continuity checks. Its daring to try to hook up 12 volts to the right lead, I wouldnt recommend it. Other things may go wrong???? Test lites are even daring here. Use the digital volt/ohm meter.

From that plug, continuity should be checked all the way to the back to check for open (broken wire?) wiring to brake light ckt. (at least I would, before getting out the steering wheel puller.) Testing the switch itself can be done here but it can be confusing. The fACTORY price is about right for pulling the steering whel and replacing the turn signal switch. Bet you can do it yourself if you also have a book and puller. Save yourself $150 and do it.

If you now feel lost, write back, I've probably forgotten something anyway.

 

Thanks to both you and Smarklkk for responses.Blazingsaddle, I don't know that I have the skills to do some of the troubleshooting you described. But your reply gave me a lot of good insight into how all of this stuff works (or why it doesn't).

It might be helpful if I gave you and others more background. I had a new battery installed in January 2006 at my local service station. The other one was five and a half years old, starting to slow down, and had started to leak. Everything was fine. Then Thursday night after work when I started up, I heard a faint, but high pitched hum that seemed to get a little louder when I accelerated but got quieter when I slowed down. I pulled into the grocery store to pick up a few things. When I shut off the ignition, everything went, including the power doors, windows, dome light that usually comes on when you shut off the engine. For a few moments, I thought I was trapped inside because it wouldn't restart. I waited a couple of minutes and when I tried a second time, it started, but stalled a couple of times before it was alright, but the low pitched hum was still there. I was only a few blocks from home so I thought I would try to get home. It was OK then all of the dash lights started flickering on and off and some of the gauges, like the fuel tank, stopped working then recovered. This continued until I got home. I shut the car off. Later in the evening, I tried starting it, and it was completely dead--nothing.

I talked with a couple of friends, one thought it might be the battery, one thought it might be the alternator. I didn't think it was the battery as it was almost new. I was concerned it might be something even worse with the electrical system; so I decided to take it to the dealer who I thought might have more experience with electrical issues. They first tested the battery and found it had a dead cell. So I had to replace that. They then checked the "charging system" which includes the alternator and found no problems. However, in the process they couldn't get the valet button under the dash to turn off the alarm system. So I told them to disconnecting the alarm system as I had not used it for a couple of years anyway after I lost the remote transmitter. However, I had never had problems with shutting off the alarm system with the valet button previously.

I do not know for sure that the brake lights or hazard lights did not work prior to taking it in. I hadn't used the hazard lights in ages. However, yesterday morning someone pulled up beside me and told me my brake lights were out. I immediately drove back to the dealership. I figured they had messed something up in disconnecting the alarm system. Also after they supposedly disconnected the alarm system, the small red "on" light for it on my dash now came on when I started the truck and stayed on (flickering) the entire time I was driving.

The same mechanic was there. I asked him to reconnect the alarm system to see if it made a difference with the brake lights. He opened the hood and reconnected the wire he had disconnected the previous day. The alarm went off, and another mechanic tried to shut if off with the valet button. It didn't work. They hadn't told me the day before that they tried to shut it off with the hood up. The alarm system views that as an invasion. I told them to shut the hood and activate the valet button, and it worked.

unfortunately, the brake lights and hazard lights still didn't work. He checked the bulbs and they were fine. They then tried to tell me it was my alarm system because the wiring for the brakes runs through the alarm system and they thought the alarm system may have lost its programming. This was apparently a guess on their part. I asked why the hazard lights didn't work and they didn't know. Meanwhile, the mechanic jiggled the turn signal while clicking the hazard light switch on and off, and they came on momentarily. He

 

Just to go back over something. FUSES???? If you think you checked them; do it again??? Please? It's often good to simply take them out, check them by looking closely and then reinserting them. Even better just to spend a few bucks and replace the ones that are associated with the problem. This is generally good advise. The fuse can be blown and not see it. The holder can be dirty and so on.

Yes alarm does activate lites. I thought it activated regular emergency flasher ckt as if it was the emergency flasher. Are you saying your emergency flasher also doesnt work? If not, change it. Your turn signals do work, right? I missed the comment about the hazard lites, just re-read the post. Dummy me.

Hazard flasher is in front of the switch for the hazard lights. The Lights that flash are the same as brake lites. So if the contact on the emergency flasher is bad, there could easily be a problem with the brake lites.

This is the path: STOP/HAZARD fuse to flasher to HAZAD switch. AFTER the hazad switch it goes through the turn signal switching. Now this is an oversimplyfied way of putting it, but for talking purposes this is it. If I were checking the wiring I would have to check the HAZARD switch as a real possible problem or the flasher, but if I were you I'd just replace it.

Other path is for turn signals and starts with the TURN/BACK-UP fuse. We know that one is good, right?
STOP HAZARD fuse is also good if the top strip is working. So perhaps checking fuses is not needed, but after an event like you describe, Id replace every one.


THE HUMMM? If this didnt come through your audio system, then I would have suspected the alternator. But then again, perhaps the hazard flasher made noise before it went??

A relay can easily HUM also. There ought to be a relay connection between the alarm and the car itself. The relay would activate the flashing lites throught the hazard system by operating.


Had to add this after thinking.
This is only opinion, have no print on that alarm system. It would not be smart if chevy built the ssytem so that the hazard switch could not overide the alrm system. It would also be extremely bad engineering if the alarm system coould actually cause a failure by having a problem with a relay in this area. I say this with a little tongue and cheek cause its also easier and simpler to build the ckt to go through the alrm and give it control. I am hoping that chevy would have thought this improper and unsafe. If you can find a diagram on this alarm system, and the way it connects to the car and grabs its working ckts, supply us with a link and I'll tell you.

 

I could have sworn that I had already posted this data not too long ago and, because of the similarities in the titles, I thought this was the same thread as the one listed below. Read through there. I have posted the recall notice for this exact problem and have the wiring diagrams at my disposal to help you out.

Have fun.

https://blazerforum.com/m_20829/tm.htm

 

swartlkk and blazing saddle, thanks for all of this information. I am learning a lot.

swartlkk, I did do a search on "brake lights" as a topic/subject in this forum before writing, but I didn't turn up the messages in your link. Perhaps I didn't do the search correctly. Your link with info on the recall notice was very helpful. I went to the nhtsa web site and read the whole recall notice, and it described the problem to a tee. The recall also applies to 2001 Blazers. Then I had a sense of deja vu. I went through my service records, and sure enough the multifunction switch they refer to in the recall notice was supposedly replaced by the dealer in 2004 when I had the vehicle in for some other service. At the time, I was having no problems with the brake lights or hazard lights. (As background, I had the same alarm system which was installed when I bought the vehicle in 2001.)

Is it possible that it's the multifucntion switch again--that it went bad in just 2 years? I hate to sound cynical, but I don't know for sure that it was replaced in 2004. I didn't ask for the old part back.