Automatic Climate Control Problems? Try This!!

Post by **phat78ta** » 18 Feb 2010, 16:47

I will begin by saying that Volvo makes an awesome car.
I recently started having issues with my ECC unit. The dreaded flashing lights. So I pulled codes, and found lots of issues, the temp fan, the blower motor, damper motor and others. I thought that the ECC control unit had given up the ghost. After looking into it, I found the temp sensor was working correctly, and the blower motor was woking properly also. Upon looking into the damper motor, I found that it was not working.
So, like any good do it yourselfer, I took the damper motor apart. I figured if it's broken, I can't break it anymore. Upon opening the housing, I found the circuit board covered in white grease. I cleaned some of it off before this pic:

The black half circles were covered in grease also. I cleaned it off, and plugged it back in. all the codes went away, and the motor operated normally.
These contacts touch the black half circles:

The grease is from the gears in the reduction system, and must have gotten on the contacts over the years.
Put everything back together, and all is well.
So, If you get the dreaded flashing lights, this is one more place to check before replacing parts.

Post by **matthew1** » 18 Feb 2010, 19:00

Good work! Entered into the Repair Database.

FCPEURO · Post by **FCPEURO** » 18 Feb 2010, 19:33

Awesome find. I never thought to pull one of the motors apart to see if they could be fixed. I just assumed that when they go, they go.

Post by **phat78ta** » 19 Feb 2010, 15:14

I thought the same thing too, so that's why I tore it apart. Kind of a silly design to make a critical contact that way, but maybe it has something to do with the position of the gear.

Post by **JDS60R** » 19 Feb 2010, 21:56

While you are in there you can clean the contacts with a pencil eraser (go lightly) . Leave the half circles alone . If you wish to replace the grease use any silicone grease like syl -glide or any dilectric compound. The placement of the grease is to keep the electricity from jumping from one circle to another.

Great job on the write up

OUS · Post by **OUS** » 05 Jun 2010, 18:25

Where and what is the damper motor?

Darksidechris · Post by **Darksidechris** » 24 Jun 2010, 13:59

Hi all,
I would also like to know where the damper motor is as I have problems with my climate control and want to try this fix before replacing anything expensive.

Thanks for an amazing site and forums, I've read loads of very helpful stuff and excellent how-to guides.

Chris.

nightc1 · Post by **nightc1** » 24 Jun 2010, 14:52

Darksidechris wrote:Hi all,
I would also like to know where the damper motor is as I have problems with my climate control and want to try this fix before replacing anything expensive.

Thanks for an amazing site and forums, I've read loads of very helpful stuff and excellent how-to guides.

Chris.

It's behind the glove compartment and the lower dash panel on the passenger side.

Here's a thread with schematic pictures so you can see where it connects to the guts under there...
https://www.matthewsvolvosite.com/forums ... 4&p=123684

As for what it is... it's the thing that directs which ducts the air is going to go in the airconditioning/heating system.

V850B5254T · Post by **V850B5254T** » 18 Oct 2010, 01:13

The use of silicone grease or oil in any electromechanical devices like potentiometers (as here) or relays is questionable.
Most silicone based products will produce Silicium Oxide (SiO2) if exposed to a spark and SiO2 is an excellent isolator.
When the wiper in the pictured example slides over the resistor half circle it will produce small sparks, not visible to the eye.

I would use a calcium stearate based grease or siilar like Luberex from GC for the potentiometer.
Silicone and electromechanical parts just does't mix.

oakey

V850B5254T · Post by **V850B5254T** » 18 Oct 2010, 01:24

The grease shown in the picture was used to protect the plastic cog wheels from wear. It is possible that the grease has entered the potentiometer and caused your problem. However, it is more possible that scrapings from the half circle resistor on the PCB has clogged the connection between wiper and resistor.
Never use silicone products for electro mechanical parts.
I would use a calcium stearate based grease or similar like Luberex from GC for the potentiometer.
HAM radio homepages has a lot of information about how to handle and repair electronics.

oakey