S40 Temp Dial Question/Problem

Post by **drvolvo** » 01 Jun 2009, 11:02

The temperature dial control in my 2001 S40 has been taking awhile (5-15 minutes) to switch from a cool setting to a warmer setting (or more dramatically to go from the coldest setting to the hottest). I just had my AC recharged as vegasjetskier suggested but it hasn't cleared up the problem.

If the system is low on freon, that may be why it takes so long to get cool air. I'd take it in for the recharge and see where you're at then.

The problem goes both ways, it either takes awhile to get cold air or hot air. In any case, the mechanic suggested exploratory surgery (taking off the dashboard and looking for pinched cables, etc.)

Anyone have any ideas about what might be going on? Anyone have a similar problem? Thanks!

Post by **vegasjetskier** » 01 Jun 2009, 14:10

drvolvo wrote:The temperature dial control in my 2001 S40 has been taking awhile (5-15 minutes) to switch from a cool setting to a warmer setting (or more dramatically to go from the coldest setting to the hottest). I just had my AC recharged as vegasjetskier suggested but it hasn't cleared up the problem.

If the system is low on freon, that may be why it takes so long to get cool air. I'd take it in for the recharge and see where you're at then.
The problem goes both ways, it either takes awhile to get cold air or hot air. In any case, the mechanic suggested exploratory surgery (taking off the dashboard and looking for pinched cables, etc.)

Anyone have any ideas about what might be going on? Anyone have a similar problem? Thanks!

Could be a sticking/defective damper motor.

Post by **vegasjetskier** » 01 Jun 2009, 14:20

Here's how to access the damper motor. I would expose it and then adjust the temp control and watch the damper motor to see if it moves.

S40SoundproofingPanelRemoval2001.pdf: (32.36 KiB) Downloaded 337 times

S40RadioPanel2001.pdf: (65.69 KiB) Downloaded 347 times

S40TempDamperMotor2001.pdf: (44.43 KiB) Downloaded 314 times

Post by **drvolvo** » 01 Jun 2009, 15:32

Thanks for the response and the pdfs! Those images really helped. I was able to view the mechanism by removing the radio. When I turned the dial, I didn't always see immediate movement. The dial goes from hottest (84) down incrementally to 60 (coldest). I found that the mechanism would move to fully open at 84 degrees by as I incrementally turned the dial down (each notch is 2 degrees) the mechanism wouldn't move or would move slightly, but by 76 degrees, the mechanism appeared to be fully in the opposite (cold ) position. So it is as if the car treats 60-76 as one setting (coldest) and then moves a bit for 76-82 and is fully open for 84. Sometimes if the mechanism didn't move to fully open at 84 I could tap the mechanical arm and it would switch over. So maybe the motor is going but its weird that the mechanism doesn't respond for so many temperatures (60-76) and then (most often but not always) moves for the hottest setting. Could it be a computer sync problem between the motor and the dial itself, where the motor thinks its at a different temperature and thus won't move. In any case, how hard/expensive would it be to replace the damper motor. I'd probably take it to my mechanic. Is this a major job (in time or parts). I like to mentally prepare my wallet for these things.

Post by **vegasjetskier** » 01 Jun 2009, 16:35

The motor is about $125. You should be able to install it yourself with the directions above.

The problem could also be the Climate Control Unit, which costs a lot more.

Post by **drvolvo** » 01 Jun 2009, 18:42

You are the best vegasjetskier!!! If nothing else, I can just manually remove the radio and tweak the lever. I just went out and played around with the damper mechanism and it wasn't responding to anything, so I just removed the pivoting bar from the motor housing to move the damper myself. After turning the dial a bit, the mechanism started working again, so I re-hooked up the arm and now it responds to all temperature settings (unlike before). Who knows if this is temporary fix or not but at least I know I can manually fix the damper myself. It's not a classy solution but it sure is a cheap solution!

I'll keep you updated as to what happens next, but thank you SO much for the advice and diagrams.

Post by **vegasjetskier** » 01 Jun 2009, 18:52

You're welcome. Glad you got it working.

Post by **drvolvo** » 04 Jun 2009, 23:29

So I found a downside to being a cheapskate... in moving the radio to fiddle with the stuck/defective/dying damper motor I managed to loosen the wires controlling the left and right front speakers (figures!). Every other bump the speakers would go in an out. I fixed that with a little extra fiddling (and its is holding for now), but now I think I should just go ahead and fix the darn damper motor so I don't have to keep moving the radio and creating new problems.

I read in the Haynes manual that once installed, the new actuator needs to be calibrated with the volvo software. (control module reprogrammed to ensure the ECC system functions correctly)

Also the PDFs posted above mention adjusting the motor after replacement. (See Temperature on the TempDamper pdf. )

So my question is, how much should/would an independent volvo shop charge to calibrate the already installed new actuator assuming I cannot do this step myself? (And if I can do this step myself, could you provide that pdf?)

In advance..THANKS!!

Post by **MadeInJapan** » 05 Jun 2009, 04:50

VADIS says that if the unit is replaced or the linkage is removed, recalibration is necessary. You might get lucky here and not need it. Just try to fix it and see what happens. If it needs recalibration, the dealer will probably charge you a minimum of their 1 hour fee- but you might be able to negotiate, depending on the dealer.

Post by **vegasjetskier** » 05 Jun 2009, 08:21

drvolvo wrote:I read in the Haynes manual that once installed, the new actuator needs to be calibrated with the volvo software. (control module reprogrammed to ensure the ECC system functions correctly)

Also the PDFs posted above mention adjusting the motor after replacement. (See Temperature on the TempDamper pdf. )

So my question is, how much should/would an independent volvo shop charge to calibrate the already installed new actuator assuming I cannot do this step myself? (And if I can do this step myself, could you provide that pdf?)

In advance..THANKS!!

Here are the PDFs. From my reading of them it sounds like you might be able to get away with setting the control arm in the same position as the old one. Then the computer will go by the info from the old damper motor and might get you in the ballpark, although the temp might be off some. Also, I don't know what would happen if the computer thinks the dampener is not at its limit and tries to keep pushing it to the limit - maybe it would burn the motor out. It would be best to take it in to Volvo the have the limits set if you can.

If it were me, I'd open up the old damper motor first to see if I could fix it. Maybe you can post a how-to?

S40-2001-DamperMotorSelfAdjustment-1.pdf: (127.31 KiB) Downloaded 304 times

S40-2001-TemperatureDamperMotorAdjustment.pdf: (40.41 KiB) Downloaded 256 times