Heating Issue :-(

[Chevy2FL]

HI. New to the forum and need help. 04 TB with roughly 84K miles. Living in England (military fam), so not much help for a US Spec vehicle... Heat wasn't working at all. Had a friend replace the thermostat, flush the radiator and replace coolant. Heat now works on passenger side only. Rear vents blow cold air and driver side is cold as well. Dash vents have not worked since we had the car shipped... Assuming it's the actuators... Not too concerned about that, just need my heat to work (even if it's just floor and defrost) so that my kids don't freeze to death. Also noticed that since the thermostat was changed, the truck idles funny when I turn on the defrost... Acts like it wants to quit on me, but hasn't yet.

Husband is in the desert and I am not very mechanically savvy. Just trying to get some ideas to pass along to my friend that is helping me out. Taking it to a shop over here will cost me a fortune...

 

[gmac310]

There are a couple of issues here. First is the rough idle issue that has to do with having a dirty throttle body. It needs to be removed and cleaned front and back of the throttle plate. The second issue regarding the heat is that there is an actuator for hot and cold too so when you say the actuatos are no big deal actually is if you want heat to both sides of dash along with the proper vent. There are various posts on here along with schematics to show what actuator does what.

 

[jrSS]

With the rough idle.....clean the throttle body with some throttle body cleaner. Take it off don't spray the cleaner while the tb is still bolted on.
Are u throwing any codes?? U could be misfiring from a bad coilpack.
Your HVAC for ur heat and AC is under the rear seat. Its called the bcm. Check there to make sure no fues are blown.

Oh and by the way WELCOME to the nation.

 

[gboos]

Had the same issues some years ago with crazy idle runs and actuator issues with hot and cold air.

First I cleaned the the throttle body and made a long reset (like 60min with - off the battery). In same step the position of the actuators were reset, but with AC held in manual mode with changing blowing positions constantly for 4 days, it started to run properly like new during this time.

 

[irwinmb5]

Sometimes those actuators can get lazy and when you disconnect the battery it pushes it over the edge. That happened to mine a few years ago and I did the reset and it has been going strong since. The link below outlines the reset process. I'm always a little worried when I disconnect the battery as to what is going to stop working. One of the many perks of a GMT owner.

[SOLVED] A/C cold only on passenger side. - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

 

[Wooluf1952]

Welcome

In case you haven't heard:
http://gmtnation.com/f5/welcome-gmtnation-com-heres-story-226/

Definitely clean the throttle body first: GMTNation - How to Clean an 4.2 Inline 6 Throttle Body

After the cleaning, reconnect the battery cable, turn the key to the RUN position, but do not start the engine for at least 90 seconds. You should hear the mode doors re-setting. Then start the truck and check the HVAC settings for the proper air flow. This should cost under $10 for the throttle body spray cleaner.
If that doesn't fix the heat problem, come on back. We're here to help.