Help Locating vent control actuator

[nfoss]

According to my dealer, my 97 GT has electrical actuators under the dash that control whether or not the vents get a/c air or engine air. It's a non-dual manual control system, and I've looked under the dash but can't find what he described.

Supposedly, I should be able to use a multimeter to test if one is bad or not - my A/C system works, but I get no cold air, hence the actuator test. I think the vent control is stuck.

Note this is not the turn dial itself I am talking about, but the actuator it controls.

[BNaylor]

Are you looking for the temperature actuator or the vacuum operated actuator(s) because they are definitely there if you look hard enough under the dash.

[nfoss]

I'm not sure - what's the difference between the two, in terms of functionality?

[BNaylor]

Originally Posted by nfoss

I'm not sure - what's the difference between the two, in terms of functionality?

The temperature actuator is the one controlled by the temp control on the climate control unit. It operates the blend door at the heater core/evaporator assembly area. The other vacuum/electrical operated actuators are used for direction of airflow. Controlling vent mode, defrost, floor vents, A/C max/recirculate, etc.

[nfoss]

OK, well it's the temperature actuator I'm trying to find. I've been told my car has electrical actuators - I'm not sure if there are different types of temp. actuators.

Could you give me a basic description of what it looks like and where it is under the dash (how deep, driver/pass side, etc)?

You've been a big help so far.

[BNaylor]

The temp actuator is supposed to be round. Basically, it is a motor and there will be a wiring harness going to it. I do not have a manual only non-dual cimate HVAC so I really don't know where it is located. But you can start by dropping the glovebox and looking to the upper left. Use a flashlight. On dual climate control systems that is the location of the one for the passenger side temperature actuator so it may be similar. It not then it will be located on the drivers side/left of the center area of the dash.

Also, if you listen very carefully you may be able to hear the motor as you adjust the temperature control from hot to cold and vice versa.

[richtazz]

For the manual A/C, it is located on the drivers side near the center console kinda high up under the dash. It is basically triangular in shape and mounts with three screws. The Delco part number is 15-72634 (GM# 89018395).

here is a link to the picture on AC-Delco's website
http://198.208.187.182/internet/View...umber=15-72634

[nfoss]

OK, I think I found that one. Actually, the more I think about it, I'm not sure which actuator I need to replace. I get cold air out of half of my front vents, but the vent direction changes perfectly (MAX all the way to defrost/floor, and back).

AND, my temperature changes OK - going from all cold to all hot, I can feel the air change, and a little 'whirring' as something moves. Close to despair here, because nothing is consistent enough for me to nail it down.

[BNaylor]

The actuator sounds OK. It is at least making the whirring sound. The HVAC is more complicated than what people believe. The other problem is you cannot see what is happening underneath. Although the actuator may check out it connects to a device called a temperature valve located in the lower heater/evaporator assembly.

Send me a PM and I'll send you a PDF file that covers the HVAC to give you a better understanding of it.

[WickdZ]

Originally Posted by bnaylor

The actuator sounds OK. It is at least making the whirring sound. The HVAC is more complicated than what people believe. The other problem is you cannot see what is happening underneath. Although the actuator may check out it connects to a device called a temperature valve located in the lower heater/evaporator assembly.

Send me a PM and I'll send you a PDF file that covers the HVAC to give you a better understanding of it.

Can you send that to me (ttl52 @ hotmail.com), as well? I seem to get ice cold air on the pass. side, but the drivers side does not get as cold. Car is a 99 GTP with dual zone climate control, if it matters. It is really bothering me.

[BNaylor]

Originally Posted by WickdZ

Can you send that to me (ttl52 @ hotmail.com), as well? I seem to get ice cold air on the pass. side, but the drivers side does not get as cold. Car is a 99 GTP with dual zone climate control, if it matters. It is really bothering me.

You got it. File sent. Good luck!