No Heat from Passenger Side Vents

[02Blazin]

Hi All:

First post here. I have been search for a few days now and haven't been able to find the answer anywhere so I figured I would post new. I have a 2002 TB LT. The other day the passenger side vents started pushing cold air only, no heat. The driver side vents push heat just fine. I have the Dual Digital Heat system and have no clue were to begin to fix this. Any one with any ideas, I would greatly appreciate it. It is getting really cold here in Nebraska now and I need that heater working as I regularly transport my 15 month daughter in the TB.

Thanks in advance.
Mike

 

[gmcman]

Sounds like one of the actuators are taking a dive, I have this problem with mine but on the drivers side....it won't fully give me cold a/c in the summer.

The dealer wants an arm and a leg to change them out, by looking at them they seem to be somewhat easy to replace just set aside an hour or so.

Wish I could say for sure but sounds like that what may be happening.

 

[Me007gold]

Sounds like one of the actuators are taking a dive, I have this problem with mine but on the drivers side....it won't fully give me cold a/c in the summer.

The dealer wants an arm and a leg to change them out, by looking at them they seem to be somewhat easy to replace just set aside an hour or so.

Wish I could say for sure but sounds like that what may be happening.

30 minutes, all you need is a Phillips head screw driver, and a 5.5mm(I think) socket. A hand ratchet makes this job a piece of cake.

 

[The_Roadie]

Jammed or broken passenger side temperature actuator is probably it. Have you recently changed batteries, disconnected it, or totally discharged it and needed a jump? Loss of voltage to the control module memory will trigger a recalibration process that can kill some actuators. You might try another recalibration.

Pull HVAC B fuse #36 in the rear fuse block (under the rear seat - driver's side) for 2 minutes. Then put it back in with the ignition off. Then turn the key to the RUN position, but don't start the engine. Don't touch the HVAC controls for 2 minutes, and you should hear the actuators and blower motor going through all the modes and speeds.

If that doesn't work, be prepared to pull some dash panels and observe the actuator as you move the passenger's side temp control.

You don't have to take off the entire dash as I did for another project here, but the metal support is in the way of easily removing the actuator for replacement. You can bend or cut it as required - you have my permission.

View attachment 18633

 

[02Blazin]

Thank you very much for the quick replies. I will see if i can figure this out.

 

[EAnton781]

Hey Roadie,

I've got the same problem on the Drivers-side temp actuator. I've already replaced the mode actuator without removing the entire dash, but I can't remember how accessible the Drivers-side temp actuator is. Do you have a pic of that side? Will I be able to get it out and replaced by only removing the bottom panels like I did before?

P.S. I've got the manual temp control, not digital.

 

[02Blazin]

Jammed or broken passenger side temperature actuator is probably it. Have you recently changed batteries, disconnected it, or totally discharged it and needed a jump? Loss of voltage to the control module memory will trigger a recalibration process that can kill some actuators. You might try another recalibration.

Pull HVAC B fuse #36 in the rear fuse block (under the rear seat - driver's side) for 2 minutes. Then put it back in with the ignition off. Then turn the key to the RUN position, but don't start the engine. Don't touch the HVAC controls for 2 minutes, and you should hear the actuators and blower motor going through all the modes and speeds.

If that doesn't work, be prepared to pull some dash panels and observe the actuator as you move the passenger's side temp control.

You don't have to take off the entire dash as I did for another project here, but the metal support is in the way of easily removing the actuator for replacement. You can bend or cut it as required - you have my permission.

View attachment 3798 View attachment 3799

Well I am back again. I finally got around to doing this fix since we had a mild winter last year I just dealt with the problem. I just changed out the passenger temp actuator today and upon taking the car for a drive after I was done, I have come to the conclusion that this wasn't the issue. I installed a brand new actuator and the passenger side still has cold air coming out no matter if I have the temp on cold or hot. If I put it to hot the driver side pushes out cold air but not the passenger side. Anyone with ideas as to what this might be now? also, I noticed that now when i turn on the AC/Heater if I come to a stop the idle RPMs drop and the oil pressure guage drops and a warning comes on on the dash saying that I have low oil pressure, if it says this way for a while it tells me to stop the engine. if i turn the AC/Heat off is solves the problem and the RPMs go back up and the oil pressure goes back up?.....any ideas would be great help. I am trying to do this myself to save money, however I might have to break down and take it somewhere...

Thanks
02Blazin
Mike

 

[02Blazin]

Forgot to include that I also changed out the Passenger Duct Air Sensor to see if that might be it, however I am still getting cold air only from the passenger side, as well as the problem with the idle speed/oil pressure when i use the AC/Heater when the TB is running.

 

[The_Roadie]

If you look at the axle of the temp actuator as you move the control, does it not move?

Erratic idle is almost always a dirty throttle body.

 

[02Blazin]

If you look at the axle of the temp actuator as you move the control, does it not move?

Erratic idle is almost always a dirty throttle body.

The axle does not move while moving the temp control for the passenger side. I did a reset like mentioned above removing the fuse and watched it then and it did move all the way one direction and then all the way back the other direction and stopped, however after running it for a little while I attempted to adjust the temperature control on the passenger side and the axle did not move at all. It is still having the problem with the low idle/low oil pressure when running the AC/Heater. If it is a dirty throttle body, how can i fix that?

Thanks Roadie!

Mike

 

[The_Roadie]

Our Article section has a lot us useful data, as well as the forum section (we haven't been working on too much lately, sorry) "Article Submission"

Here's the throttle body cleaning link: GMTNation - How to Clean an 4.2 Inline 6 Throttle Body

You may have a wiring or control module issue. Can you find somebody to trade modules with? Do you want to get into the wiring harness and look at the signals? Do you have an independent mechanic with a GM Tech II tool which can communicate with the HVAC system and command the actuator to move and check the position feedback sensor?

If you just want temp back for the winter, you might consider doing the fuse pull reset, and while the actuator is in the process of figuring out where its endppoints are, yank its connector to freeze it in a position that gives you some heat.

 

[02Blazin]

So I broke down and took it in for diagnostics. Found out the temp door is broken. They wanted almost 1K to fix it so I ordered the 62.00 part and am going to tackle the project on my own. Anyone have a diagram to show how to pull off the dash and other supports to get to the HVAC system?

Also cleaned the throttle body. Working better but still have the issue every now and then, am going to clean it again and see if that helps.
Thanks Roadie!

 

[The_Roadie]

The factory shop manual available in paper only, is the best resource for this.

 

[02Blazin]

The factory shop manual available in paper only, is the best resource for this.

Is this something I could get my hands on? (Buy somewhere?) or maybe on online version somewhere for free?