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
This was exactly what was wrong with my 2007 Trailblazer. Thank you so much! Now that’s it’s cold I’m so happy to have my heater working again.
Absolutely no programming or calibration needed for replacing the electrical portion of the ignition switch as shown in this repair post.
If you were to replace the lock cylinder you may have to do a theft relearn procedure. They may be referring to that.
What problem are you trying to fix?
So I have a 2006 Trailblazer that the the dealer says needs the ignition switch replaced. They are telling me $275 and that its not something my husband can do b/c it will need to be recalibrated. Is this true?
Glad your a/c is back working. The stalling problem is from a dirty throttle plate. You disconnected the battery and the computer’s learned memory was erased. Over time it will relearn but it may take a while. If you want to you can clean the throttle body and be back in good shape. To clean the throttle body you will need to remove the rubber and plastic intake tube assembly. Use a screw driver handle to hold the throttle plate open, KEY OFF. Spray throttle body cleaner on a rag and wipe out the throttle body bore and the edges of the throttle plate. You will want to wear several layers of nitrile gloves or thick rubber gloves of some sort. The cleaner can irritate your skin. DO NOT SPRAY the throttle body cleaner into the throttle body assembly. It will be a $500 US mistake.
WOW! We did exactly what the video said to do and it took care of the problem like a charm! We aren’t mechanics and were a little hesitant to do it ourselves, but with a little encouragement, elbow grease and a prayer; we switched out the ignition switch for a new one and the ac began to blow and the abs light and the brake light didn’t come back on like before. The vehicle seemed to want to stall out when stopped at a light and running the ac, but gunning the gas and running the vehicle at 55-60 mph on a stretch of highway for about 5-10 minutes took care of that. Thank you sincerely. All of our friends will know about you.