Whatever I press, air only goes to the windshield. I guess it's the famous mode servo gone haywire. Lots of DIYs and info for 2nd gen, less so for us lot. I did find the attached parts diagram online, but I'm not sure which servo to buy. There are four listed:

• 87106D SERVO SUB-ASSEMBLY, DAMPER, No.1. SERVO SUB-ASSY, DAMP 8710630440
• 87106H SERVO SUB-ASSEMBLY, DAMPER (FOR AIRMIX). SERVO SUB-ASSY, DAMP; NO.1 8710630430
• 87106H SERVO SUB-ASSEMBLY, DAMPER (FOR AIRMIX). SERVO SUB-ASSY, DAMP; NO.2 8710630450
• 87106L SERVO SUB-ASSEMBLY, DAMPER. SERVO SUB-ASSY, DAMP 8710630480

The first column is the reference to the attached image, the last number is the actual part number. I guess the two 87106Hs can be ruled out, they're for the driver and passenger heat control. I also guess that out of 87106D and 87106L, one controls where the air goes to ("mode"), and the other controls fresh air vs recirculation? At least that's how it seems to be on the 2nd gen... But which is which?

My gut feeling is that the 87106D is the "mode" and the 87106L is the recirculation. This is based on the D being next to the windscreen outlet at the top of the "radiator assembly" and the L being next to the fan in the "blower assembly". Can anyone provide any insight? Dealer is useless, wants $100 for a "diagnostic" before they'll lift a finger.

Lastly, is this sort of problem on the GS 3rd gen usually the servo, or is there something else I should check out?

 

Bump - any clues about these servos? Winter is coming...

 

It looks like someone made a DIY guide on how to access these servos, here.

Hope this helps!

 

Wow, you must be psychic! I just found it, and I'm going through it. About to remove the glovebox, hope it's not too complex back there! I'll report back with my findings. The windscreen vent only seems to blow cold air, so I'm starting to be cold in the car. However, I think there is more than one problem. There is certainly more than one symptom:

• Air only comes out of windscreen vent.
• Said air is always cold, whatever the temperature is set to.
• Yet, adjusting the temperature does seem to affect the vent that blows to the rear seat passengers. I need to confirm this, but I'm 80% certain.

Anyone got any clues what all this means? I'd tear my hair out if I had any.

 

Update - I've taken the glovebox out, and I can see what's going on. All three servos (air direction, temperature, and recirculation), seem to be doing the job. Funnily enough, the recirculation door was stuck on the filter, which had not been fitted correctly, but it's fine now.

Given that the air direction servo moves when I press the buttons, I have no idea what to do next. I guess I need to take that servo out and take a closer look. Any tips will be welcome.

 

Another update. This is really weird. I took out the air direction servo, and have tried manipulating the lever on the white plastic air duct manually. The air *still* doesn't come out of anything apart from the windshield. Is there another mechanism at work here? Some kind of bypass?

Should I take a look on the drivers side of the dash? There's definitely some clicking around when I turn the ignition on and off, and it's none of the three servos that I can see on the passenger side.

Basically, I'm totally out of ideas.

 

So, I took a look at the driver side. This is much more difficult to get to. The lower of the two servos there moves whenever the temperature is moved. The upper one, which is such a ***** that I gave up for the night, doesn't seem to move at all, and it seems to be connected to some cogs.

I'm referring to the diagram in the first post from here on:

Things I know about the passenger side:

• Indeed 87106L is the recirculation servo.
• 87106D plays at least some part in the mode-switching. I'm guessing it's the windscreen on/off.
• The 87106H (No 1) is the passenger temperature.

Things I know about the driver side:

• The lower 87106H (No 2) is the driver temperature.

At this point, my hypothesis is that the top 87106H (No 2) on the drivers side is the one that is responsible for diverting air to the face and floor vents. But I won't know until later today, because it's so hard to get to. I think I'll have to remove the driver's knee airbag.

 

This interesting and I'm sure you won't get lots of replies since most ppl don't venture this far into the dash on their own. I was trying to figure out something similar with my 460 which has about 17 servos. I was not getting heat but it turned out to be a partially clogged heater core which was easier to fix.

 

Yes, I see that nobody seems to know about this on the 3rd gen... Here's a photo from under the driver's dash. It clearly shows the floor vent on the right, and the two 87106H servos. The lower one is definitely the driver's side temperature. The upper one is the one that I think (hope) diverts the air. Again, it is a ***** to get to. I've removed the part of the floor vent visible in the shot, but the access is still tricky. I'll try later removing the next part of the floor vent, and moving the knee airbag out of the way. My main mission is to remove the servo, then I'll be able to manually actuate whatever it's connected to, and see if it's connected to the air diversion.

 

Updated above photo link to work.

 

Thanks for the updates! This seems like a chore, for sure ... Keep us posted!

 

Will do. Just haven't had time this week, due to work... With the battery unplugged for 30 minutes, I should be okay to unplug the airbags, right?

 

I hear ya ... Another day, another twenty five cents!

The airbags shouldn't be an issue. I would just exercise extreme caution when working on or around them.

 

The driver's (left) knee airbag makes it really difficult to get up high in the dash. I'd love to remove it. Is it just a case of unplugging? I had a go at the passenger knee airbag, it's unscrewed along with the glove box, but the plug is in and didn't come out easily, so I left it. But really I'd like to know if they should just unplug. It's a big part of continuing this.

 

Okay, so here's the latest update. I was right about the upper servo controlling the mode. Upon removing it:

1. When I change mode with the climate control buttons e.g. floor to face, it moves! The servo isn't faulty!
2. When I try to move the thing that the servo is supposed to move (the half-moon in the top-middle-left of the photo below), it doesn't want to move! The big cog in the middle doesn't want to move either! I think it's something mechanical in the system, but I don't know where to go next. I think I might admit defeat and go to the dealer. Or try and pull off the white panel.

Any clues gratefully appreciated!