History:
1997 Cadillac Deville, 41K miles.

1. When I got it in March, it had a "Low refrigerant, AC compressor off" message. No cooling.
2. A month later, it developed some whirring, squeaky actuator noises behind the radio. Usually, at the start, like it it was trying to set/reset back to its last known settings?
3. Cleared the codes. Low Refrigerant light remained on for a couple of weeks. Now its gone (?)
4. Had a code ACM B1340 Air Mix Door #1 Movement Failure. Explain the motor noises, maybe. But door # 1 is supposed to be the driver'* side. I don't see any actuators driver'* side.
5. Wacthed a video for a 1998 DeVille where he approached it from the driver'* side. Cut the vent to access the actuators. I see none of that on mine. All my actuators are behind the glove box/passenger side. Driver side just has those round parts that the colored vacuum hoses attach to.
   Sparky'* Answers - 1998 Cadillac Deville, Passenger Side Vents Hot with A/C On
6. Mine seem to be part of one larger vent box on passenger side, one actuator on top and one smaller one on the bottom. See pix below.
7. When turning the heat up, the top actuator does move but seems to be the source of the moaning. Heat all the way up, it would go all the way to right. Heat down, it would go to left.
8. After a finger bump, the bottom one started working. Seemed in sync with top one. Kind of.
9. Using the passenger-side temp **** on the armrest does not affect either actuator. Not sure if its suppposed to.
10. Here is video of the top actuator moanng when in use. Seems to be the right actuator itself. Lubrication didnt do much. but didnt ecpect it to.
    https://iplayerhd.com/player/video/0...c8b20697/share
11. (New) Whenever Auto or Defrost is on the compressor fan clutch now clicks (loudly) on and off every 5 seconds. Video. Put it on Econ it stops. The click on and off is louder than it sounds here with the engine running.
    https://iplayerhd.com/player/video/1...519cc0bd/share

Questions:

1. Where the hell did the Low Refrigerant Compressor Off message go and why? ;^)
2. Is it possible that my only actuators are the two behind the glovebox?
3. The top actuator seems to have only three nuts holding it on. It'* not the easiest space to work in. When pulling it, should I pay attention to any gear/cam settings?
4. Also, the top actuator runs off of a metal rod that runs through the length of the vent housing out the bottom (red box in picture). If that'* the issue, or something in that main large vent box housing, does anyone have any experience there? That looks no fun to access or disassemble.

The changing symptoms and symptoms are confusing me.

As always, many thanks! Going to beat this into submission yet.

Driver'* side only has these round actuators. One for each colored vacuum hoses.

Click in the breadcrumbs to move around.

Operation CHARM: Car repair manuals for everyone.
Home >> Cadillac >> 1997 >> DeVille V8-4.6L VIN Y >> Repair and Diagnosis >> Heating and Air Conditioning >> Control Module HVAC >> Service and Repair

Control Module HVAC: Service and Repair

Remove or Disconnect
1. Negative battery cable.
2. Right-side sound insulator and glove box unit.
3. Vacuum and electrical connectors from programmer.
4. Programmer from vehicle.

Install or Connect
1. Programmer to vehicle.
2. Vacuum and electrical connectors to programmer.
3. Right-side sound insulator and glove box unit.
4. Negative battery cable.
pro multis · About Operation CHARM

Thanks. Found the steps for ATC:

https://charm.li/Cadillac/1997/DeVil...8RPO%20C68%29/

Once again, I'm grateful for your support, fellow enthusiasts! I've installed two new actuators, both labeled as genuine GM AC Delco from Rock Auto, but interestingly, they came in slightly different boxes, and each bears a different manufacturer'* name/stamp.



Regardless, it is quieter (although there are still a couple of noises, but I think they will be less with the trim back on). And they move freely, and the system is sending cool air now where before there was none (and a low refrigerant message on the dash?). It was not cold but noticeably cooler, and raising the heat sent heat where it needed to go. I think I still need refrigerant recharge. I let the computer recalibrate on install. Steps said to turn the ignition to ON and let it do its thing for 3 minutes. During these 3 minutes it did nothing at all. I then raised the temp to 90 and both actautors went far right. Went to 60 and both actuators went far left.

My only question now: when the top actuator went far right, its metal rod went over the top white plastic actuator arm - it is actually touching it. And the arm is farther right than the original went (but then again, the original was broken). Is that normal to touch and go on top? Should it stop short of actually rubbing/touching (thats what she said). If supposed to be in sync, the bottom metal arm does not quite go far enough to go over the top and touch the plastic actuator arm.

Here'* how to reset the system.AC reset
Turn the system on full cold Max AC. Blower off.
Radio OFF.
Turn ignition OFF.
Pull the HVAC (AC) fuse(*) from interior fuse box. Leave out for 1 minute and replace.
Turn key to run/on position....NOT start.
Do not touch any controls. You'll hear the doors (actuators) being opened and closed. The HVAC module is learning the full open and full close positions. Wait until the system is completely done with the learning process. Less than a minute.
If you hear clicking while the system learns it'* a failing actuator.
Start and test the system.

Thanks carfixer007 for the procedure!

I wouldn't worry about that rod touching the arm. By the shape of it, it looks like they expected this.

Yes, thanks! I will do the reset because I did have a lowe refrigersnt message (which went away on its own?) And also had the B1340 coxe for actuator door failure I need to reset.

Thanks. I ran the reset. There is no "interior" fuse box that I could find in my 1997 trunk and engine compartment. Am I missing one? There was an AC fuse by the air cleaner in the driver'* side engine compartment. I pulled that one and waited the minute. The actuators did nothing at all—no movement or sound. Maybe they are already reset?

There'* one in the trunk. From page 6-66 of your owner'* manual:



I bet [IGN 0-BODY] and [COMFORT] are what you're looking for.