An actuator is a device which actuates something else - especially a mechanism which causes a device to be switched on or off.
the blend door actuater is bad
First disconnect the battery, remove the door panel and pretty straight forward from there.
There is a part called an actuater. It looks like a plunger. They are natorious for dry rotting and the four wheel drive being engaged is on a vaccuum system that involves the actuater. Once that gets a hole in it, it stops the vaccuum and will not engage. It costs about 65 dollars and is about a 15 minute job to fix. It is located under your car battery. Remove your battery and the battery plate that your battery sits on and you will then be able to see the actuater. Once you see it, it is self explanitory on how to remove. Call your local gmc dealer to obtain part.
You will need to allow the seat belt to retract completely, and if this does not work there is a problem with the actuater and you will need to take it in for service.
There is a box located in front of the left front tire,it has two connectors and is by your air pump.Has the word guide on it with two 10mm bolts holding it
The lock actuator has failed on whichever doors are making the noise. The actuater is serviced with the door latch.
If you are talking about the ign switch and not key switch. It is located under the dash, mounted on top the steering column
Put it on jack stand. If the four wheel does not engage pull the cord on it and see if you can engage it manualy. If that works the actuater is bad and not pulling the cord.
the blend door actuater is more than likely the cause of the noise.....very common....can go in behind the glove box to replace it.
It could be the problem. The dealer can scan the code with a Tech II unit they have. www.trailvoy.com The Trailblazer enthusiast forum!
if you can hear your transfer case kick in and your front wheels arnt kickin in theres a electronic actuater in the front end that always goes its ownly like 50-60 bucks
You can find detailed instructions on how to replace an door actuator and control valve on 2008 Pontiac g5 on youtube.com/watch?v=ttIZ_iCLFGo