850 Blower motor

0230683 · Post by **0230683** » 10 Sep 2012, 16:15

My 850 blower motor ( climate control ) only runs when the switch is on high ( #4 ) I don't want to replace the motor if the switch is the problem. Any trouble shooting tips? Thanks, ken

Post by **misha** » 10 Sep 2012, 19:19

Did you checked the fuses?

There is a fuse for speed 1-3 & a fuse for 4 speed.

Also...what climate control you have...manual or electronic(auto)?

Manual console only have red & blue colors on the temperature sides and ecc(electronic climate control)console have addition of degrees(numbers on the teperature sides).

Post by **Ozark Lee** » 11 Sep 2012, 09:29

Chances are it is the blower resistor if the fuse is good.

...Lee

0230683 · Post by **0230683** » 11 Sep 2012, 16:56

Haven't checked the fuse(s) yet because the motor runs on high. My system is old school - manual - Is the resistor accessable without removing the motor.... is it replacable , repairable or internal? Ken

Post by **Ozark Lee** » 11 Sep 2012, 20:25

The resistor is inset into the air duct, just to the left of the blower. They have a thermal fuse that can go bad and have heard of people soldering in a new one. In my case the wires just burned up and there isn't any real fix for that beyond replacing it.

The resistor is here:

: DSC02578.JPG (207.96 KiB) Viewed 1843 times

The large blue wire goes to the resistor but in your case it will look a little different and there won't be a blue wire, the picture is from a car with the ECC. The resistor is in the same place on both versions.

There are two fuses for the fan, fuse #5 is for speed 4 and fuse #31 is for speeds 1 to 3.

...Lee

Post by **BEJinFbk** » 12 Sep 2012, 01:08

There have been reports of the issue that you've described being caused by a bad switch.
In your position, I would download the wiring diagrams for your car, get familiar with
the MCC section and start with a look at the resistor pack, as recommended by Lee.

https://www.matthewsvolvosite.com/volvo-wiring-diagrams

Since the blower speed switch output wires run directly to the resistor pack,
this will put you in the right part of the dash to check the output of the switch
at the same time and reduce your dash disassembly time troubleshooting efforts.

0230683 · Post by **0230683** » 12 Sep 2012, 12:58

Thanks all for the info. I've been driving / working on Volvos for a long time. I never noticed there were two fuses for the blower motor. They are both good by the way. Thanks again.

Post by **misha** » 12 Sep 2012, 16:30

Then,it should be a bad switch or a bad resistor.There is no 3rd option.

Roadrunner · Post by **Roadrunner** » 13 Sep 2012, 15:36

I also have this blower problem now. Though I see the led next to the A/C switch is not glowing and if I trip the REC switch it also does nothing. As steated early if I slide the fan speaed bar over to Max or AUG - nothing. Forgot to say I have a 93 850 manual (with out a fuse box cover). I was wondering if those relays Lee stated could be also my problem? The motor was working fine one night and the next day nothing. Also can a slow leak in the heater core can caouse this also? (car smell sweet when the heater is turned on.) For info the A/c pump does not work. Third request, I saw a repair posting of the sun roof window gasket (rubber ring) can some one who knows what it is call Pm it to me for the last bit of down poors we had in Springfield Virginia has caused my car to be damp on the inside. (I am thinking about using rubber gasket and just seal it).
I hope the repairs I asked help on do not required to much dismantling of the car for I have few tools and really no work space.
Does any one near Springfield, Virginia know of a shop that will rent you a bay with hand and air tools included? I use to have a repair shop like this back in California but that was many years back. Thanks for the help. Frank

Post by **kcodyjr** » 13 Sep 2012, 18:45

Roadrunner, sounds to me like you've got a blown fuse; even if you did have a failed resistor, the A/C and REC lights should glow appropriately. Since you've got a 93, go pull the ECC codes and see what it says.