This 2003 Chevrolet Trailblazer came in with the complaint that the blower would not work on any speed and that the Brake and ABS lights stay on. Since I have seen this problem before, I knew right where to go to test. then ignition switch. The first thing that has to be done is to remove the tilt lever handle. Some just pull straight out but this one was a little difficult so I used a screwdriver for leverage.
After the lever is pulled past the detent it comes out easily the rest of the way.
Now the trim panels under the dash have to come out. Two screws, 7mm, for the black hush panel under the dash.
With the black panel down there are two screws that hold the bottom of the knee bolster panel.
Two at the top of the panel.
Then the panel will unsnap. Someone has already been here. The spring clips are missing.
Now there is a soft piece of rubber trim at the rear of the lower cover. It needs to be worked loose of the lower cover. Then carefully unsnap the lower cover and work it loose from the column and the soft rubber piece in the rear. Some models may require removing the steering wheel to get the cover off and some may have screws in the underside of the lower cover.
Now that the switch wiring is exposed. Check for constant battery power on the red wire as shown below.
Turn the ignition on and check for power on the orange wire. We have just diagnosed a faulty ignition switch.
To remove the switch, I first gently pulled the wiring for the key buzzer and /or antitheft antenna out of the retainer as shown below.
There is a special GM tool for releasing the ignition switch retainers but I just use a couple of pocket screwdrivers. There are two white spring loaded pins that have to be pushed in to allow the switch to come out.
You can now see the two pins exposed as I pulled the switch down.
GM says to remove the lock cylinder and use a tool to fully rotate the inner mechanism but I don’t bother. I just make sure the ignition is off. Key out. Pull the switch down and note the position of the gear teeth. DO NOT rotate the gear teeth. Adjust the teeth on the new switch to match the old switch position.
The wiring harness lock is a little difficult to release. You are supposed to depress the locking tab.
I was having a problem so wedged my screwdriver between the switch housing and lifted it instead. If something breaks, I would rather break an old part that is being replaced, instead of the latch on the harness connector. Makes sense, right?
I checked the harness connector for damage and all was okay.
Maybe a better view of the plug in connection to the switch.
I adjusted the gear teeth to the same position. I also compared them one behind the other to check the alignment.
The new switch on the right with the gray cover. To purchase the new updated ignition switch please click here.
Slide the new switch into place until the spring loaded locking tabs click into place.
Plug the wiring harness back up to the switch. Positioned the rest of the wiring back into the retainer on the side of the switch.
Cranked the engine and checked the blower and all is well. Time to finish installing the rest of the parts.
To see the video for this repair please click here.
This ignition switch fits the following vehicles, however the repair procedure may vary between these vehicles.
2001-2005 Pontiac Aztek
2002-2004 Oldsmobile Bravada
2002-2007 Buick Rendezvous
2002-2009 Chevrolet Trailblazer
2002-2009 GMC Envoy
2003-2006 Cadillac Escalade
2003-2006 Chevrolet SSR
2003-2006 Chevrolet Suburban
2003-2006 GMC Savana
2003-2006 GMC Yukon
2003-2007 Chevrolet Silverado
2003-2007 Chevrolet Express
2003-2007 GMC Sierra
2003-2007 Hummer H2
2003-2008 Isuzu Ascender
2004-2006 Chevrolet Tahoe
2005-2007 Buick Rainier
2006 Chevrolet Avalanche
2006-2009 Saab 9-7X
More than likely you have more than one problem. I would strongly recommend looking at the circuit breakers in the rear fuse box and make sure that they are not getting hot. If they are remove them and check for a short. Had one come in a few years ago that almost burnt up the truck.
Sparky,
I’ve had some similar electrical gremlins running through my 2004 Trailblazer. I may have a combination of problems???
Started with blower only working on 4 and 5. Now blower only works on 5.
Next, the reduced engine power light came on and I was basically stalled out in my driveway. Shut off the truck, restarted it, issue has been gone since.
Then the ABS and Parking Brake lights came one. Continued with this problem for one afternoon and has been gone since.
Now the tail lights, parking lights, and dash lights won’t turn off when I shut off the vehicle. In addition to that the rear glass won’t open (button doesn’t work) and when I opened the rear hatch last night I could hear the locking / latching mechanism repeatedly actuating.
All of this has happened in about the last 2 weeks. What the heck is going on? I have problems from front to back with this vehicle.
Was the battery disconnected for the three months that it was parked? I would suggest getting the codes read and starting with diagnosing that first.
Hi Sparky thank you for all the knowldge and videos,
I have some weird issue if you can help me with it.
I have trailblazer 2006 LS ext, it’s very well kept and i do maintenance regularly
I parked the car for 3 months and it was fine then, when i came back i tried to start the car it started OK, then engine turned off, then cranked a little bit it started with “engine check ” light.
it worked OK but each day in the morning, when i start the car “engine check is on” but the car starts OK then after 1 -2 minutes lights of Traction control and reduced power come on and the engine dies.
i try to start again but it won’t crank and all 3 lights are one after waiting for 5 minutes it starts OK and it works fine for the rest of the day with engine check light on.
every morning i have the same story, i noticed one thing i don’t know if it’s related, after the engine die if i rock “shake ” the car i can start it immediately without waiting.
I sent the car to dealer and it seems they don’t know what is wrong, they suggesting to replace all the electrical wiring and loom in the car !!! for 2700 USD!!
would you please help me with this issue
You or your mechanic should start by checking for power on the orange wire at the ignition switch with the key on. No power would mean the switch or connector is faulty. Possibly the switch is not properly timed. If power is present at that orange wire then there is an open circuit somewhere else. It would also indicate that proper testing was not done before the ignition switch was replaced.