Hvac issues

So, I have no idea what's wrong with my system. I have no heat, only cold air on the driver's side. I replaced the mix actuator, but it would only move to cold, no matter what temperature I set it to. I can manually move the controller to have hot or cold air, but the actuator will only set it for cold. It won't blend or turn to hot.
Any advice is massively appreciated I just want my full range of temperature back again lol
Also the passenger side works perfectly just to note that

Bloo the 98 riv wrote:

So, I have no idea what's wrong with my system. I have no heat, only cold air on the driver's side. I replaced the mix actuator, but it would only move to cold, no matter what temperature I set it to. I can manually move the controller to have hot or cold air, but the actuator will only set it for cold. It won't blend or turn to hot.
Any advice is massively appreciated I just want my full range of temperature back again lol
Also the passenger side works perfectly just to note that

Start by checking all the actuators, which will take a while.

albertj wrote:

Bloo the 98 riv wrote:

So, I have no idea what's wrong with my system. I have no heat, only cold air on the driver's side. I replaced the mix actuator, but it would only move to cold, no matter what temperature I set it to. I can manually move the controller to have hot or cold air, but the actuator will only set it for cold. It won't blend or turn to hot.
Any advice is massively appreciated I just want my full range of temperature back again lol
Also the passenger side works perfectly just to note that

Start by checking all the actuators, which will take a while.  

I did check them all. They all work if I take the blend door off. The middle one moves freely, but when I put it back on the knob, it will move it to cold air, then stop moving, and then won't change it to hot, even though I can manually turn the air to hot with it off.

I have a similar problem... everythin in the car was working fine a month ago, but now the AC only comes out of the passenger side. Driver's side is perpetually just outside air temps.

Bloo the 98 riv wrote:

albertj wrote:

Bloo the 98 riv wrote:

So, I have no idea what's wrong with my system. I have no heat, only cold air on the driver's side. I replaced the mix actuator, but it would only move to cold, no matter what temperature I set it to. I can manually move the controller to have hot or cold air, but the actuator will only set it for cold. It won't blend or turn to hot.
Any advice is massively appreciated I just want my full range of temperature back again lol
Also the passenger side works perfectly just to note that

Start by checking all the actuators, which will take a while.  

I did check them all. They all work if I take the blend door off. The middle one moves freely, but when I put it back on the knob, it will move it to cold air, then stop moving, and then won't change it to hot, even though I can manually turn the air to hot with it off.

Apology for my response delay.

Most likely the large positioning gear in the actuator is broken. You can buy them via eBay or Amazon, just search for "gm hvac actuator repair kit"

These actuators were designed years ago (not quite as far back as when Methuselah was a pup but I'm thinking 50 or so years ago at this point) to use metal gears.  They were 'updated' to use plastic gears and the plastic gears ALL fail eventually. almost always well after the warranty period but yes they all fail.  Some of the actuators continue to work correctly after the gear fails, others do not.

If you luck up on an older (70s-80s) GM vehicle you may be able to remove the metal gear from their actuator and put it into yours.

However, the actuator repair gears work well & are a once-and-done repair (different material).

To figure out if you need actuator gear(s) just remove the actuators one by one and pry them apart.  It will be obvous, the retaining tabs are on the outside.  Helps to have a spudge (like for working on iPads) to slip under the retainer to get it over the little ridge on the actuator case.  Once inside - look at the gears - there is only one big one and almost as sure as you're living it will be cracked through, although there is a longshot chance that there will be a broken tooth or two on some minor gear.  

The different actuators have part numbers on the outside.  If you just have the big gear broken, cheap way out is to buy the kit with the big gear.  If the motor is dead, cheap way out is use the part number off the actuator case and do a web search to find a replacement. The actuators may be obsolete part numbers BUT there are **lots** of them around, both used and (on Amazon at least) new, as GM IIRC is still using versions and configurations of them in various cars.

ADDvanced wrote:

I have a similar problem... everythin in the car was working fine a month ago, but now the AC only comes out of the passenger side.  Driver's side is perpetually just outside air temps.

Similar answer to that above. Pull and check the actuators.

Yup, just haven't gotten to it yet, and less important as summer is ending. Appreciate all your help, Albert!

ADDvanced wrote:

Yup, just haven't gotten to it yet, and less important as summer is ending.   Appreciate all your help, Albert!

YW. You can see some of the actuators work without removing them by looking up and in from the driver or passenger fotwell respectively. You can reach most of them that way but IIRC it's easier to take the dash apart a little. I don't remember if that was needed except for one of the actuators on each side.

In about 15 minutes you can suss out what's going on with the actuators you can see.

In order for the defroster to work right you're going to have to fix these especially the blend door actuator. The HVAC control head depends on running the AC to dry out air then run that drier air over the heater coil in order to get things right. It is because of this (IMHO) that the driver and passenger door window defrosters work at all.