Temp control on driver side

[QuestionQuest]

Browsing the forum I didn't see much info about the issue my vehicle is having but here goes. My 2005 Quest is having an issue with the temp control on the driver side. I can turn the temp down to cold but it doesn't increase when turning it back up to get heat. I can also hear the clicking noise from what I think is possibly a dreadful actuator sound coming from under dash when turning on the system but, I'm not sure which actuator this would be. Has anyone experienced this same thing on their Quest? Any help on where to begin this repair would be much appreciated. Also have an 02 A/F sensor on B1S1 to replace but that's another every bit of a day Thanks again for any input!

[VStar650CL]

The driver's mix servo is about halfway up the HVAC on the driver's side, see ATC-36 here:
https://www.nicoclub.com/service-manual ... %2Fatc.pdf

Fortunately, the driver's servo is about the only thing on a Quest HVAC that doesn't require removing the dashpad. Remove the lower left dash and there are 3 screws holding it in. See ATC-160.

[QuestionQuest]

Thanks VStar, many thanks. Great manual. Easy to get to like you said and I was suprised to find out the screws are actually 7/32 since just about everything else you put a wrench or socket to is in mm I did get the new part and tried it but still continue to have the same issue. It's getting stuck on cold. The servo moves the arms for the door okay but when its all the way down (toward the floor) is where it gets stuck. Fails to acknowledge the control knob when turning it up for heat. I put the original part back in and same thing happens. Not sure what the problem could be. Checked fuses and they're okay.For now I just left the servo out and operate the door manually

[VStar650CL]

Back-probe voltage on the Yellow/Black wire at the servo and see if it changes when the servo position moves. If not, see if you have 5V on White/Green and ground on Yellow. The position signal is a simple potentiometer, Y/B is the output (wiper). If that checks out, see if the voltage across Yellow/Green and Blue/Black changes when you try to move the temperature, if it doesn't then the motor driver in the control head is blown. You can see the setup on ATC-39.

[QuestionQuest]

Thanks I'll check it out in a couple days. I did want to mention that when i had it plugged in but just hanging down by the plug, I moved the temp control to both cool and hot but the servo didnt move at all. It did move when i shut the vehicle of but only after about 30+ seconds. I'm about to have alotta fun putting the O2 F/A ratio sensor in here in a week or so. B1S1 by the firewall