climate control is acting out

motovovo · Post by **motovovo** » 21 Dec 2010, 01:35

Hello ,

I have a 1994 850 Turbo Wagon, heat does not work neither does the defroster. I have electronic climate control and I have retrieved the following codes:

135 No signal from engine coolant temperature sensor.

231 Ventilation damper motor position sensor open circuit or shorted to

12 volts

233 Floor/defrost damper motor position sensor open circuit or shorted to

12 volts

323 Ventilation damper motor active too long

324 Floor/defrost damper motor active too long

411 Blower fan seized or drawing excessive current

414 Drivers side interior temperature sensor inlet fan seized

417 Passenger's side interior temperature inlet fan seized

The vehicle's the AC/ recirculation lights blink for a short duration upon start up. Recently I was driving on the freeway and I decided to turn on the blower to defrost the windshield, then I heard a faint click and the AC/recirculation lights started blinking (while I was driving) for a longer period of time, like twenty seconds or so. I have considered the notion that I have more than one issue going on here.

Can anyone say something about the codes that have been thrown? I disconnected the battery and got the same codes again. I am just thinking it is a blower motor...I hope? Does anybody know if code 411 definitely means the blower motor is seized??? Where is this power stage which I continuously read about in these forums? Can I test it to see if it is bad before simply throwing money at my ' 94 wagon??? If I have to dig out the fan motor from the passenger side dash panels, am I simply looking to see if the squirrel cage on the blower motor is seized up??? Thanks in advance.

Post by **jblackburn** » 21 Dec 2010, 07:24

It does sound like the blower fan has died to me, but you definitely have other issues as well, but that's the one to start at. Pull it out and see if you can get it to run with 12V directly to the motor. You may be able to get it running again with a bit of oil/silicon grease into the motor bearings. The power stage sits right next to the blower motor; once you remove the glovebox lining, you'll see it.

Your damper motors probably need some help as well; the arms may be either broken, stuck, or just taking a long time to move.

As for the temperature fans, take a can of compressed air to the little grilles in the two grab handles above the doors. Blow out any gunk you can from there. You may have to remove the grille and take a very soft brush gently to the internals.

As for the ECT sensor, do you have a check engine light? Does your temperature needle warm up quickly to the halfway position and stay there as you are driving?

Post by **phat78ta** » 21 Dec 2010, 11:22

https://www.matthewsvolvosite.com/forums ... =1&t=27239
Try this. I had a lot of the same damper motor codes and found the actual damper motor to be the culprit. worth a look.

Klausc · Post by **Klausc** » 21 Dec 2010, 15:56

Removing a battery cable will NOT erase codes from the ECC. You must go into B-1 and erase the codes using normal procedures. A lot of your codes are probably old and meaningless. Try erasing them twice and see what is left over.

If you have never put a cabin filter on your car, it didn't come with one, order a filter and filter holder. It will keep dirt, leaves, etc out of the evaporator.

If you can turn on the blower via the switch, then the blower motor is good. Unless some twigs got in there...

motovovo · Post by **motovovo** » 27 Dec 2010, 00:31

Thank you gentlemen for the help through your responses!

The fan motor appears to be back to its operational state. I previously thought the codes would be cleared by disconnecting the battery but was advised to the clear the codes through B1, which I did. All the codes went away except two, 231 and 233. despite the two remaining codes the blower motor now works. The vehicle never had any trouble getting up to operating temperature so I am satisfied for now that the climate control will work for the winter.

This is my first Volvo and I love her dearly but I never would have thought that simply clearing the codes would have made the blower motor run again. Can anyone speak to that, perhaps some ice melted away or some water dried up??? Anywho...thanks for the help.

Klausc · Post by **Klausc** » 27 Dec 2010, 09:31

Those codes refer to damper motors that are not working. The dealer wants a fortune for them, so I suggest going to Rosemount pick&pull for replacements: http://www.upullrparts.com/index.cfm/go/yard.inventory

If you put the ECC vent and fan selectors on AUTO, the unit should flash the orange lights on the recirc 20 times at each engine start - letting you know that there is an error and the auto function will not work. Moving the blower switch to the right will allow manual operation.

washdup · Post by **washdup** » 27 Dec 2010, 13:28

I just got a new aftermarket blower unit from FCP Groton for under $100. You can purchase a lifetime warranty on the part for less than $10. It functions just like the OEM unit (no louder, etc.) Good luck.

motovovo · Post by **motovovo** » 25 Jan 2011, 21:03

An update is necessary. After one month of intermittent operation the blower motor finally died. When I got to the blower motor itself, the cage was very hard to turn. The power stage had a "frosted" appearance to it which told me it was gone as well. I replaced both and everything was good again. I never did figure out a way to bench test the old power stage.

I was very close to buying a less expensive, aftermarket blower motor but was advised not to because it could not move the same volume of air, I did however replace the power stage with a used unit. Also, I was told that operating the heater fan at the lower output levels was bad for the unit because of the resistance that builds up in the blower motor....the heater should be on at "full blast" until the cabin warms up and then be shut off. Thanks again for all of the advice from everyone.

Post by **jimmy57** » 25 Jan 2011, 21:16

"Also, I was told that operating the heater fan at the lower output levels was bad for the unit because of the resistance that builds up in the blower motor....the heater should be on at "full blast" until the cabin warms up and then be shut off. "

This makes zero sense. Any brush motor wears based on speed and the number of revolutions turned with maybe a little accelerated wear for brushes when fan runs on high as brush current is highest. If you have ever run a brush type motor where the brushes can be seen, you will see electrical arcing at commutator where brushes contact when it is run full power and the arcing diminishes greatly with lower current.
The car has automatic climate control, pay attention to the road, drive safely and let the climate system worry about the fan.
If the life of fan is a concern, in about 5 years take it out and lube the bushings with some light oil.

motovovo · Post by **motovovo** » 27 Jan 2011, 17:48

"Also, I was told that operating the heater fan at the lower output levels was bad for the unit because of the resistance that builds up in the blower motor....the heater should be on at "full blast" until the cabin warms up and then be shut off. "

This makes zero sense. Any brush motor wears based on speed and the number of revolutions turned with maybe a little accelerated wear for brushes when fan runs on high as brush current is highest. If you have ever run a brush type motor where the brushes can be seen, you will see electrical arcing at commutator where brushes contact when it is run full power and the arcing diminishes greatly with lower current.

Really? Zero sense? Why is the advice so hard to understand and why does it deserve to be negated with a snide remark?

I interpreted this to mean that as the fan became harder and harder to turn over time it would be best driven by a motor at full voltage regardless of brush motor wear or commutator arching.

Regards