CRUISE CONTROL WON'T WORK ON 2005 CHEVY TRAILBLAZER

in relation to the cruise control ????? There is no vacuum used for cruise control on your vehicle . Your vehicle has a computer controlled electronic throttle system .The powertrain control module (PCM) monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed. The PCM uses the throttle actuator control (TAC) module motor in order to control the vehicle speed. For further information on the TAC system, refer to Throttle Actuator Control (TAC) System Description . Your best bet , take it to a qualified repair shop. Need a factory or some other professional type scanner to check for codes an data input from the switches to the PCM

First you need to have EBCM - electronic brake control module check for DTC'S - diagnostic trouble code's . If the light is on there is a code stored . I think most part stores can do this and for free . After you find out what code is stored , looking up that code in service repair information for diagnostic trouble shooting chart would be next step . There are a few codes too.
DTC C0035 or C0040
DTC C0045 or C0050
DTC C0110
DTC C0131
DTC C0161
DTC C0186
DTC C0196
DTC C0201
DTC C0240
DTC C0241 or P0856
DTC C0244 or P1689
DTC C0245
DTC C0283
DTC C0287
DTC C0290 or C0292
DTC C0455
DTC C0550
DTC C0558

Find the code do the diagnostic's , fix the problem , wiring issue's , a sensor , bad module ,what ever it is . The light will go out then . Here is a sample of code discription .
• DTC C0035 Left Front Wheel Speed Sensor Circuit
• DTC C0040 Right Front Wheel Speed Sensor Circuit

Have you checked transmission fluid recently. If the levels are low and/or if the dipstick smells burnt, there is a good chance your transmission is shot. Check it out & let me know; may have another idea if the fluid level checks out.

I would check the turn signal switch. The cruise and turn signal are on the same switch. The brake lights go through the switch before going to the brake lights. And the turn signals don't work with the ignition off.

CK codes c0131 ABS/TCS system pressure circuit malfunction. Their is a Technical Service Bulletin out for this that is being addressed by chevy so you may want to get in touch with them.

Hi. There happens to be a common problem with these trailblazers inside the ducting box located under the dashboard. The mode actuator door motor stops working due to a faulty motor itself and the default position is defrost only. As far as the Air Conditioning not working, there maybe another problem to diagnose there. Could be low refrigerant, or electrical problems to the compressor, or faulty fan clutch(another very common problem with these trucks). Type in mode actuator door and 2005 trailblazer in your search engine online i.e. Google or Yahoo and you will find many posts about this problem. I think there may even be a Youtube video about replacing it. Let me know you need more help. Thanks.

You are describing a dead battery.

Check the mega fuse in the underhood fuse panel, picture below

Probably not, you just won't know what's going on in your engine and your speed. What do you mean it is gone? All gauges are not moving, no warning lights on, no gear selector or odometer display?
Check fuses #22 & 24 in the underhood fuse panel. If fuses are good, problem could be a bad cluster or a break in the data lines to the cluster.

I take it that it's not working? 1 thing to keep in mind...if there are any check engine codes stored in the computer, te cruise control will be disabled. When this code is cleared out, the cruise control will work again.