The headlights will dim when driving the vehicle. This can occur when idling but mostly happens when the vehicle is at highway speed. This has happened several times and two different dealers have checked the problem and performed all applicable tsbs and replaced the BCM with no difference in the problem. The lights will dim enough that when driving on dark country roads I am not able to identify the edges of the road. Tech support claims this is normal operation of the system.

- Rockville, IN, USA

I am experiencing the same light dimming/voltage drop issue on my '05 Chevrolet Trailblazer that I saw reported by many others on the www. vehicle has been in to dealer twice for this issue, I am told that lights dimming during quick deceleration was normal, and caused by air pump. While GM may consider this normal, I objected to that characterization as itwas not acceptable to have headlights and entire electrical system dimming randomly while driving, especially at night. This presents a legitimate safety issue. How can we force GM to address this issue?

- Haddon Heights, NJ, USA

My headlights dim while driving, first noticed while driving about 25 mi. From home and they would go dim and the gage would dropbelow 14 and then they would brighten up and the gage went above 14, has done this on several occasions dealer took it home over night to see what was going on and of course it didn't do it, he showed me a print out that said not to replace the alternator that there was no problem with it, it continues to do this and it seems to me that there is a problem but until they see it I'm just stuck with it, any suggestions!.

- Circleville, OH, USA

While driving at night (more noticeable), the head lights appear to dim then brighten (flashing the vehicle ahead). While this is occuring, the battery gauge bounce drastically from min to max then back to the middle. This has been occuring since the day I bought this vehicle June 05. Also while this occurs, the vehicle tends to lose RPM power so as you are driving there is a "jerk" in the forward motion.

- Virginia Beach, VA, USA

When I start up my Trailblazer and drive off the headlights and dash lights flash and flicker. I have taken to the dealership twice for repairs and they find nothing wrong, and gave me a bulletin from GM that stated this is a normal operating characteristic due to a secondary air pump diagnostic routine, and that there is nothing to fix. I think this is wrong. The lights flash so much people think I am flashing my lights at them. If I sit and idle for 30 seconds or so, sometimes that helps, sometimes it doesn't (this was GM's "fix"). if it's cold I have to idle it for several minutes, and even then it doesn't always stop it. I have had to pull off to the side of the highway, stop my engine, start it again, wait several minutes, then merge back into traffic and just pray the lights didn't start flickering again. This should be made a recall and they should be forced to fix this. I have contacted them repeatedly and got nowhere with them.

- York Haven, PA, USA

Dimming lights on a 2005 Trailblazer and fluctuations in electrical accessories. Took to dealer twice, second time replaced alternator, they say GM states it's normal operation and the computer is drawing power and causing dimming. Other motorists think I am flashing lights at them, I am also concerned about fire.

- Stow, OH, USA

2005 Chevrolet Trailblazer's headlights flickered on and off. * sometimes the flickering last for a few seconds other times it has lasted up to 10 min. The dealer was able to duplicate the problem but stated there was a tsb from Chevrolet which stated the flickering was normal. Therefore there were no repairs attempted. The brakes pulsated due to rust on the rotors.

- Liverpool, NY, USA

We have a recurring problem with the headlights, dash lights dimming and brightening. It seems to be a common issue with most 2005 Trailblazers. This has been ongoing for several months.

- Camby, IN, USA

My wife drives a 2005 Chevrolet trail Blazer. One day about 1-2 months ago she was coming home from work, about 20 miles, and the headlights and instrument lights started flashing on and off. This happened all the way home. I took it to smith Chevrolet in laurens, S.C. (29360) to have it repaired. I was told there was no fix and Chevrolet was aware of the problem and that this was also a problem on the Envoy. I was told it was because of the drain on the electrical system when a number of components were drawing current and the smog system or pump came on. I was given a flyer that stated what could cause the problem of which none could I attribute to my wife's driving style. I have been contacted by a person saying his name is jeremy at 866-790-5700 ext. 22087. Jeremy offered to give us a 12 month 12,000 or 18,000 mile extended warranty from the date of service at smith's. the car has about 29,000 miles on it so the warranty would be for about 5,000 miles. I do not want an extended warranty. I want the car fixed, replaced or refund. This is a very dangerous situation for my wife. She is out at night with our 9 year old son and she does not feel safe. I don't know date exactly. It is estimated. This has happened a second time but not taken in yet.

- Gray Court, SC, USA

Purchased 2005 Chevrolet Trailblazer ls Oct.28 06. Since then, to date, veh. Has been in shop (dealership 4X). 1. brake repair. All 4 calipers were replaced. This vehicle had only 22,000. Miles. In shop very 1st week of purchase. 2. been complaining of flickering lights. Was handed a GMC printout stating they did not know cause. So therefore the dealership, hood Chevrolet, covington la. Could not do anything about it. 3. complained of engine acceleration while applying brake, coming to a stop or a slow speed in a parking lot. Fear that I may crash into someone. Received printout from GM stating this was normal. But I see this is a hazard. 4. complained of seat belt "riding" on the neckline, restricting blood flow in left artery on neck. I see this a major problem. I commute 26 miles one way to work at a hospital. I thought I would be safer driving my Trailblazer, now I fear for my life. 5. complained of popping on front end. Service had to order sway links and replace. Did not solve problem, still have frontal popping while turning left or right, reverse and forward. It is progressively getting worse. Found out GM certified tech. Did not properly align calibers when installed. I have paid to much for this $23,000. Lemon. Action should be taken. Sarah dykes, bogalusa Louisiana.

- Bogalusa, LA, USA

On 2 different times I have taken my 05 Trailblazer to the dealer for work to done on what we thought was the alternator. The headlamps and inside lamps will dim and the battery charge gauge will drop below the 14 amps GM call normal. I have been told that this is a normal condition. I feel it is anything but normal and it is a safety issue. People think you are bright lighting them and it is just plain hard to see at times. It seem to happen more when it is cold and damp. This is not normal, and unless GM decides to fix this problem we will not buy another GM product!

- Bauxite, AR, USA

Headlights and dash lights dim for no apparent reason. Headlights flicker, usually only momentarily but on occasion has lasted for up to 10 minutes. I feel it is illegal and unsafe to drive. GM says it is "normal"

- Liverpool, NY, USA

- the contact noticed while driving at night the headlights would go down to low beams. Once vehicle was warm he didn't have this failure. The contact stated that he could barely see the road in front of him while driving. Also, while driving and another vehicles blinked the lights to inform him that the high beams were on, but the vehicle indicator light didn't show that the high beams were on. The contact took vehicle to 4 times, and the last time was told that his air pump was the cause of this malfunction. The contact stated that he still had no resolution to the problem with his headlights. The contact has called General Motors, and they took his complaint. He was told by General Motors that they were working on this failure due to of the number of similar complaints. The contact stated tht he had no resolution from General Motors, and he has contacted the better business bureau. The BBB gave him a claim # 71438795446, and was told that they would work with general motor and see what they can do about this.

- Jerseyville, IL, USA

Night driving under normal circumstances the vehicle a Chevrolet trailblzer ls 2005 has a problem that randomly shuts off the headlights and dashboard lights. The Trailblazer decides to do this totally on its own at random. This causes a potentially deadly situation when on the interstate and your headlights go out and decide to come back on at random intervals maybe aproximately 15 to 20 seconds apart. Several attemps have been made to the Chevrolet dealership to get the problem repaired. Their comment is that they either cannot duplicate the problem or their is a service bulletin that explains the issue. I have done the procedures that the dealership described in the service bulletins with no success. Currently my Trailblazer is being repaired once again at terry lee Chevrolet as of 12-19-06. The last time that the vehicle was in for repair terry lee Chevrolet replaced what they had though was a faulty body control module. Replacing this module obviously did not rectify the problem and on Thursday 12-14-06 the problem once again returned. Since the vehicle is used to Transport my childeren and wife who have been driving primarily at night. I have become skeptical about whether or not the vehicle is safe to actually drive at night because you never know when the lights will decide to turn off by themselves and potentially cause them to be in an accident.

- Russellville, OH, USA

Headlights..for no apparent reason my headlight flash off and right back on and then flicker at a constant I have taken my Trailblazer to the dealer where I bought it several times and they say that they can't find the problem..I have had this vehicle in the shop several different times..they have replaced the instrument panel and the speedometer cable..the onstar computer now you tell me why they can't figure out what is blowing these things out..why they can't find a problem with them.

- Lenore, WV, USA

While driving to work in the early morning when it was still dark the headlights and dash board lights began to flicker. They got really dim and then came back to full brightness. This happened for a period of 15 - 20 minutes which was when I turned the vehicle off. I took the vehicle to the dealer where it was purchased and they were unable to duplicate the problem. They told me later that afternoon that GM had been contacted and that GM stated that this was a normal condition and that no repairs were warranted. I fought with the dealer and told them that it was not a normal condition and that I was unable to drive the vehicle in the dark because it caused a safety issue both to myself and to other vehicles on the road. They kept the vehicle for 3 days and then told me that GM was aware that there was in fact a problem with the air pump however they did not know what to do to fix the problem. I was also told that it will continue to do the same thing on and off in the future. This is definitely a safety issue. When this happens the cars directly in front of me and on coming traffic think that I am flashing my high beams at them not to mention that it is very distracting to me while I am driving and I am sure that eventually, whether it is my vehicle or another vehicle with the same problem, this will cause an accident. After looking through the complaints on this web site I have found 17 other vehicles with the same exact problem. The owners of those vehicles were also given the same "lame" excuse that I was given.

- Lake Hopatcong, NJ, USA

: the contact stated while driving various speeds at night, the headlights, interior dome light and the instrument panel flickered on and off without warning. The vehicle was driven to the dealer who could not duplicate the problem. Updated 11/13/06.

- Greer, SC, USA

2005 Chevy Trailblazer, headlights and interior lights dim and flash for no reason while driving (looks like a christmas tree). If I stop and shut the vehicle off, and restart, it stops. See several people having the same issue when I search on-line. Dealer claims they can find no error codes.

- Manchester Ctr, VT, USA

I have a 2005 Chevy Trailblazer lt. While driving on the highway behind a car my headlights and interior lights began to flicker ( get dim and come back on). The car in front of me thought I was flicking on my high beams on and off at him and slams on the brake. I did some research on my car and found out that a lot of the Chevy Trailblazer owners have the same problem and that Chevy can't find the cause.

- O'fallon, MO, USA

: the contact stated while driving at various speeds the automatic dash lights and headlights failed to remain illuminated at night. The failure occurred intermittently and without warning. The dealership replaced the body control module, cleaned the ground wires and inserted a snap shot in attempt to remedy the failures. Updated 07/11/06.

- Broughton, IL, USA