Climate Control Nightmares Topic is solved

[V50M66]

Well it’s nice having working ABS, but it predictably hasn’t helped with the climate situation.

Tried relearning a few times today, but it wouldn’t take. Kept spitting out the error “SKIPS DETECTED - STOP”

[scot850]

Does that mean that one of the servo motors is not rotating correctly or possibly positioned at the wrong end of it's movement cycle?

I'm no expert in these things but it is unfortunate that this is being so challenging. I've had issues before with bad servo motors and a bad cabin temp sensor as well as the predictable fan motor and resistor unit failure, but to date no actual ECC unit failures.

I should add, I have had issues with bad internal flaps where the rubber seals on the edges of the flaps have become tacky and stick when closed. 850's also had an additional issue with one of the flap shafts splitting and not rotating. Not heard of that on the V/S/C 70 though.

Good Luck!

Neil.

[xanthefin]

Well it’s nice having working ABS, but it predictably hasn’t helped with the climate situation.

Tried relearning a few times today, but it wouldn’t take. Kept spitting out the error “SKIPS DETECTED - STOP”

Maybe on some bluetooth devices when i took 50ms out of 250ms delay in Service side of the app was then more than i should for some devices. I have love and hate relationship with Android bluetooth system as not even Google own code examples have any reliable working one as they drop connection etc. with long data connections i will send patch soon revert that.
Edit: Got now time and sending update as writing. Up to Google again how long it will take until public.

[V50M66]

Does that mean that one of the servo motors is not rotating correctly or possibly positioned at the wrong end of it's movement cycle?

I'm no expert in these things but it is unfortunate that this is being so challenging. I've had issues before with bad servo motors and a bad cabin temp sensor as well as the predictable fan motor and resistor unit failure, but to date no actual ECC unit failures.

I should add, I have had issues with bad internal flaps where the rubber seals on the edges of the flaps have become tacky and stick when closed. 850's also had an additional issue with one of the flap shafts splitting and not rotating. Not heard of that on the V/S/C 70 though.

Good Luck!

Neil.

It seems the driver's blend door isn't operating as intended (or at all). Rotating the blend door itself with the motor disconnected, it rotates smoothly and freely with very little effort and doesn't stick on the ends. It does go cold by itself sometimes (then usually back to hot in a few minutes), so I don't think the positioning is wrong.

It is a real pain, that's for sure. Getting sick of it not working right.

Thanks!

[V50M66]

Started the car after work today and heard a faint but persistent clicking from the dash that lasted about 10-15 seconds. I wonder if I just need to pull the trigger on a new blend door from Volvo. Hate to spend $200 on something I can get for a few bucks at a junkyard but I haven’t been having much luck finding a 98 at the local yards and the ones out of my 99 don’t seem to be happy in this car.

[abscate]

You should be able to find a used blend door on ebay or from someone parting out a car..there are a couple in the classifieds right now

[V50M66]

At last, progress!

So after determining the blend door out of my '99 parts car didn't work properly (possibly due to a design revision that's not reflected in a changed part number), I bought a blend door motor from a '98 S70 that a member is parting out (big thank you Alex!) and it works great. Dangling by the wire (where I can see the square end), cycling the temp setting, I can see it move smoothly and as it should.

However, it doesn't change the temperature when bolted into the car.

I unbolted it, checked again, and the motor works great. I then took a flathead screwdriver and turned the blend door by hand with the fan running. It also works fine, with smooth operation and a good seal - no hot air was getting past when manually turned to cold.

I then held the motor up to where it bolts up and changed the temperature with the knob. I felt the motor turn, but the air temp didn't change. Looking up at where the motor and the blend door shaft meet, the square end is very chewed up and it's clear that the motor isn't making proper contact.

IMG_4281.jpeg (146.5 KiB) Viewed 326 times

I'm assuming the only fix for this is replacing the entire HVAC box? Is it possible to just replace this part separately?

[abscate]

You can replace just the damper by tearing down an HVAC white box. Take a good look at your evaporator as itsa good time to replace that too. Figure about 10 hours for the whole job.

I might have one in my stash thst is still moving between Albany and Stony Brook via the Bridgeport ferry every few weeks but I owe 5 people in CT parts ahead of you…

Seriously, I’ll check and post on next trip

[songzunhuang]

Ugh, this sounds like the same problem I am having as well. Didn't want to have to tear into the dash again. I replaced my evaporator many years ago. It's such a time consuming job. I'll wait for the outcome of this thread and re-evaluate just to be sure before committing.

[songzunhuang]

At last, progress!

I unbolted it, checked again, and the motor works great. I then took a flathead screwdriver and turned the blend door by hand with the fan running. It also works fine, with smooth operation and a good seal - no hot air was getting past when manually turned to cold.

I then held the motor up to where it bolts up and changed the temperature with the knob. I felt the motor turn, but the air temp didn't change. Looking up at where the motor and the blend door shaft meet, the square end is very chewed up and it's clear that the motor isn't making proper contact.

I'm assuming the only fix for this is replacing the entire HVAC box? Is it possible to just replace this part separately?

A few questions and an idea.
Can you access all this pretty easily from under the driver kick panel? Or do you have to get to it from the top by removing the dash pad? Here's a picture of when I had my white HVAC box out last time. Is the motor in question the one with the arrow?
Curious that in this picture I only see one motor. I think there is supposed to be 2.

HVAC Blend damper motor?

HVAC Blend motor.png (1.5 MiB) Viewed 298 times

Here's a picture from a seller on eBay, I think this is more accurate. Is the electric damper in question the on on the left, deeper in the dash?

Picture from eBay

HVAC Box2.jpeg (42.01 KiB) Viewed 291 times

A suggested quick fix - what if you put some dark grey JB Weld epoxy on into that recess and then mount the damper motor, wait 24 hours and then try it? Could it be possible that the JB Weld would refresh the square end that got chewed up? It maybe worth a shot before tearing into the white HVAC box. That's a major job.