1996 850R Blend Door Motor (Damper Motor) ECC

[wackenhut]

Hi,

So I have been experiencing hot air coming through the drivers side vents and cold air coming through the passenger side vents.

I brought the car to the dealership because of this...the ECC was also flashing indicating that something was wrong.

They told me that 3 of the motors have seized up and that they need to be replaced.

Anyone have experience with this? Also, are there non oem parts? Each motor is about 200 dollars.

Thank you.

[abscate]

Time for a pick and pull run at 20 USD each.

Did you get the actual ECC codes from the dealer??

My shiny new Autel 802 gives me the Volvo codes now...humblebrag

[wackenhut]

They did not give me the actual codes (I did pay for the diagnostic though). They also mentioned that there is also another blend door motor that switches to defrost that is not working. Does anyone have part numbers? I keep looking and everyone says that all 5 or 6 motors are the same part number. The dealer said that 2 are the same and one is different...maybe the one for the defroster?

I know that the one on the driver side is not working. Also, does anyone know if all damper motors are accessible without removing the dash?

Any help appreciated.

Thank you.

[scot850]

There is a great write up for replacing the evaporator that cover many of the issues you will have to deal with in terms of access.

This is well worth a read if nothing else to get familiar with the layout and where the motors are. 2-3 are easier to access, 1 on the LH side is a pain and the last at the nearest the firewall on the RH side is a major pain.

http://www.woodjoiner.com/volvo/VolvoEvapReplace.pdf

There are from memory 5 motors on an 850, and they are all the same. On the S/V70 there are only 3 motors and one on the LH side to the right of the steering wheel has a different drive shaft on it. The other 2 and all 850s have the same motor. The 850 ones are easiest to get to if you go to a PnP type place to get them. I pulled 3 at our local PnP last weekend at 50% of day and got all 3 and a TCV for $16 CDN (or $4 each) or $12 US!!

But before you run off screaming lets tackle the (relatively) easy stuff first.

There are many things that can go wrong, and some are easier to fix than others. If you eventually have to pull the whole system out, you might as well consider replacing the heater core and evaporator while in there. Allow at least a weekend for this or more worst case.

So easy stuff:

1) There are 2 cabin temperature sensors in an 850 ECC system. They are situated behind the grab handles above the front doors in the roof. These have little fan motors in them that pull cabin air through from each side and sense the cabin temp on that side and the system then adjusts accordingly. Over time, airborne crap gets in and clogs the fans and they can't sense the temp correctly. They are fairly easy to access, but removing the grab handles, pulling down on the top of the door seal (I think I haven't done this in about 5 years) and you have to pull the plastic trim piece off above the door frame. You can now get access to the little sensor fan unit. Carefully remove and use cotton buds and rubbing alcohol (90% IPA) and a small artists brush to clean the crap out. Careful not to damage the temperature bead in the middle. With these clean, temporarily re-install the sensors and switch on the car and see if the little fans are running. This doesn't say they are good, but at least the circuit is good.

Check now if you are getting better temp. control on both sides.

2)Next, pull the glove box out (see info attached on how-to). Also drop the 2 dash under-trays down and out. You should now be able to locate the 5 motors. This is where I would call the dealer and ask for the codes so we can help identify which, if any, motors to look into. Even without the codes there are a few checks you can do. With the system on, turn the recirculation setting on and look at the motor directly behind the glove box, to the left of the fan motor. There is a lever arm on the motor shaft that often breaks with age. See if the arm moves and the arm is good. If all is good then move on. If not, the motor can be removed by undoing a small screw at the front edge closest to you and the motor should slide out giving access to the arm if you need to replace. Not sure if the air is still available (called the intermediate arm Part #: 6808653) and if it is replace or try and find one at PnP that is good.

3) Next check the motor you can see to the left of the glove box opening. The servo motors have a square shaft and it goes into a plastic sleeve. This sleeve splits with age, or because the flap on the end of the shaft kind of melts and sticks, causing the motor to overdrive and brake the plastic end. Again, this section can be disassembled without removing the dash. Remove the motor and check the shaft end is good. If not, try gluing with epoxy and then reinforce with a small worn clamp or pull a zip-tie tight to hold it. Try to turn the flap and check it moves easily.
If memory serves the flap at that end can be replaced by removing a few screws on the side of the unit. Can't find the part number for that. There is a flap at the other side, and it is no longer available. If that is sticking, only choice is to see if you can get one from a PnP that is better.

The other 3 motors can be removed, but make sure you know their position of their shafts when you take them out to make sure they know their home positions. on 95 and earlier you could run a reset program so the system would reset the motors correctly. I don't know how to do this with a 96/97/98.

At least you will then be able to see if any motors are actually bad. I've only ever had one go bad on me, it was usually the flaps that are the problem.

If you can get the codes, we can help you target your time more effectively.

Hope this is of help.

Neil.

[jreed]

I had similar problems as the original poster. I read the codes, took out the damper motors, marked the orientation of the gear, cleaned the contacts inside, reset the position of the gear to the original mark, and reinstalled. I reset the ECC codes and all has been working well for the past 2-3 years (knock on wood... hopefully it will keep on working well!)

Illustrated write up available here:
https://www.matthewsvolvosite.com/forums ... 5&p=251432
Not a bad job but it is a bit tight under the dashboard to get access to the screws holding the damper motors in place.
Good luck!

[Klausc]

The motors seldom fail, but the position sensors can get out of alignment and cause the same error message as a failure. Mechanics/dealers don't like to work on the ECC system, very few know how to work the hand held computer for a proper diagnosis.

With multiple errors, such as yours, it is best to remove the dash. Not terribly difficult, and you will need a place to store the dash and steering wheel.

I took all 4 motors out of my 1996, carefully pried them apart, cleaned them, put the position sensor in the middle of the range, closed them up, and carefully reinstalled them after moving the vents to the center point of the opening.

I found out that the center vents had pushed past the close position and were stuck in place. Also, the right hand shaft had broken plastic, which I glued/clamped back in place.

Then using 3 wires and an LED, I made my own diagnostic tool. This emmulates the old OBD1 system and flashes the LED to give you the codes.

After the car was all buttoned up, I entered the 9-9-9 code to reset the vent limits and drove a mile above 20mph. All have worked since. No need to buy a motor.

[wackenhut]

So 3 of the 5 damper motors are being replaced by the dealer. One on the drivers side and then 2 on the passenger side. I paid a diagnostic fee, so everything should already be removed to install the new parts. Anyone know how many hours in labor I should be charged?

Also, does the diagnostic fee usually go towards the repair if I supply the parts, or is this a separate cost?

[JimBee]

I had this problem on my first Volvo, a 93 850. It was the motor shaft on the right side of the console, left of the glove box. I had no heat to the drivers footwell.

I discovered that the motor was activating but the receiving plastic shaft that accepts a square drive metal output shaft from the motor had split, so the flap wasn't operating. I think I stuck a screwdriver up the vent outlet and popped the flap free—it seemed stuck, maybe from pollen or something.

Anyway, I discovered that a 10mm i.d. bushing (also 10 mm long, if I recall correctly) slips over the plastic shaft and can hold the shaft together so it turns with the drive motor shaft. That has worked through 6 winters, so far—the force be willing, it will continue.

[abscate]

So 3 of the 5 damper motors are being replaced by the dealer. One on the drivers side and then 2 on the passenger side. I paid a diagnostic fee, so everything should already be removed to install the new parts. Anyone know how many hours in labor I should be charged?

Also, does the diagnostic fee usually go towards the repair if I supply the parts, or is this a separate cost?

Usually not, but square this away with the dealer before work starts. Looking for a problem and removing parts are two different things.

You will likely have trouble getting a dealer to use your own parts without a pretty big disclaimer.

[wackenhut]

Yeah, thank you. They did give me a disclaimer that the parts or service will not have any warranty. I am okay with that as long as the issue is resolved. I just can't see paying 200 dollars a piece for brand new damper motors.

How long should it take a volvo mechanic to replace the driver side temperature damper motor, passenger side temperature damper motor, and defroster damper motor?