2002 TB engine dies when turning on AC

I have a 2002 TB EXT that recently due to warmer weather I turned the AC on and the engine sputted and died. Truck started right back up and ran fine as long as I didnt turn the AC on. Scared, I just burned up till I got home and then did some tests to see when it actually does this.(and if it would do it everytime) It dies instantly when the AC is turned on, and when in heat mode, only when you use any of the defrost modes. The defrost modes however doesnt make the engine die, just idles roughly. I am planning on taking it to the dealer next week, but wondered if anyone had any ideas of what this could be and how much my rear end will hurt when their done. or is this something simple...:screwy:

Welcome to AF. Disconnect the wire to the ac compressor see what happens, may be seized

Thanks for response. Does anyone know how much it will run me to replace the compressor?

At a dealer with the addt'l work necessary, probably 1,200. Diagnose it 1st.

Its been a while since I wrote, I the compressor is not siezed, it works fine, air that comes out is cold also. I had the fuel system cleaned thinking that maybe the throttle body was gunked up, (it was pretty bad, however the truck still idles up and down and if I am not moving, it will eventually idle down so low it stalls. Any additional advice?:screwy:

tkazee, did you ever get this fixed?.. I have the very same problem.. Thanks...jp

No I havent yet, We recently experienced some snow earlier than expected and I had to replace tires. As with everything with this vehicle, nothing is ever fast, easy, or cheap so I have to build up to take it to the shop. :banghead:

We disconnected the compressor and it still either dies (when the AC is on) or idles up and down when in defrost mode. Could it be a sensor?:screwy:

tkazee, did you ever get this fixed?.. I have the very same problem.. Thanks...jp

did you ever get yours fixed?

posted in the GMC forum.....

could try this,clean the throttle body bore.here is a bulletin showing you how.Engine Stalls When Air Conditioning Is Turned On at Idle2004-2007 Buick Rainier
2002-2007 Chevrolet Trailblazer and Trailblazer EXT
2002-2007 GMC Envoy, Envoy XL and Envoy XUV
2002-2004 Oldsmobile Bravada
2005-2007 Saab 97xEngine may stall with the air-conditioner on and or while adding additional loads to the engine at idle. An example of an addition load would be turning the steering wheel left or right with the air-conditioning on. This type of stall usually occurs during idle or slow parking lot maneuvers. This concern may not set any diagnostic trouble codes.
Clean the throttle body bore and the throttle valve plate using a clean shop towel with GM top engine cleaner, GM P/N 1052626 (Canadian P/N 993026) or AC-Delco Carburetor Tune-Up Conditioner, P/N X66-P, or an equivalent product. this should help.

posted in the GMC forum.....

could try this,clean the throttle body bore.here is a bulletin showing you how.Engine Stalls When Air Conditioning Is Turned On at Idle2004-2007 Buick Rainier
2002-2007 Chevrolet Trailblazer and Trailblazer EXT
2002-2007 GMC Envoy, Envoy XL and Envoy XUV
2002-2004 Oldsmobile Bravada
2005-2007 Saab 97xEngine may stall with the air-conditioner on and or while adding additional loads to the engine at idle. An example of an addition load would be turning the steering wheel left or right with the air-conditioning on. This type of stall usually occurs during idle or slow parking lot maneuvers. This concern may not set any diagnostic trouble codes.
Clean the throttle body bore and the throttle valve plate using a clean shop towel with GM top engine cleaner, GM P/N 1052626 (Canadian P/N 993026) or AC-Delco Carburetor Tune-Up Conditioner, P/N X66-P, or an equivalent product. this should help.

Actually this is one of the first things that we did. :confused: Sorry I didnt post that. We also changed did a tune up, oil changed as well. It still does it.

So did you ever get this figured out?

Just wanted to post a follow up; and give some back ground information.

My daughter was going to work in the 02 Trlblzr and stopped at the gas station; after filling up (christ is that expensive!), she went to start the truck and it wouldn't start. She calls me crying, because she is stuck at the gas pump and will be late to work.

I met her at the gas station, had her pop the hood and checked the battery voltage, it was at 12.42vDC; had her turn the key over to start and the voltage dropped down to 4.21vDC.

We jumped the Trlblzr off of my S10 and got it going. Off to Advance we went and had the battery changed...

Next day on her way to work, she turns on the AC while at a stop light. The Trlblzr shuddered, RPMs surged and sagged and finally the truck died. She got it started again and then another crying phone call...

I checked here yesterday to see if anyone else had experienced the same problems; some had, but with no follow up posts to explain any type of resolution...

So I went to the local Chevy dealership after work and went to the service department. I explained everything in detail and the guy looked at me with a slight twinkle in his eye and said.... "You can bring it in and we will reprogram her truck on with our computer"; to which I replied, "So every time someone has to replace their battery, they have to bring it back to the dealership to get it reprogramed, sounds like on hell of a scam to me!". At this point the guy quit smiling at me and said to drive the truck around with the AC on to "Re-learn" the computer idle settings. Well the daughter and I did just that after she got home from work; at first the engine continued to surge and sag but after about 5 miles of driving on city streets and highway, it quit surging and sagging.

I called her this morning after she got to work and she said that there was no problem, it worked fine.

A little long winded, but hey you wanted to know (you read it!)

if the motor dies when turning the a/c on, then all it needs is a simple throttle body cleaning. it should take about 15-20 minutes and should fix the problem. Be sure to disconnect the battery when doing this so the PCM can relearn the new parameters.

Im now only just having these issues and after cleaning the throttle body have see a yvast improvment.