1993 Volvo 850 blower motor resistor location

loyd198 · Post by **loyd198** » 17 Oct 2009, 13:00

I have a 1993 Volvo 850 GLT and I am needing to replace the blower motor resistor. I know it is behind the glovebox..but that's all I know. Can someone tell me the exact location of the resistor and what it looks like. A diagram or pictures would be very helpful also. Thanks

Post by **MadeInJapan** » 17 Oct 2009, 13:09

You should have two (one for lower fan speeds and one for full blast). They are circles in the diagram below.

: Blower motor resistors.jpg (80.61 KiB) Viewed 16763 times

Post by **BEJinFbk** » 17 Oct 2009, 14:16

MIJ - I think you're confusing resistors with relay. You've circled relay.
And before this goes any further, the first thing to do is identify which
climate control system is being discussed. Manual (MCC) or Electronic (ECC).

The fan speed control is the give away here. The MCC has a stepped fan speed
that shows "1-2-3-4", while the ECC is continuously variable.
Which applies for this '93 ?

Post by **MadeInJapan** » 17 Oct 2009, 15:23

Ah... sorry about that. Yes, answering the question that is posed will further help you.

Post by **Ozark Lee** » 17 Oct 2009, 15:24

The blower motor resistor (or power stage in the case of the ECC) is inset into the air duct directly to the right of the relay(s) that are shown in MIJ's picture. With the ECC there is only the A/C relay, on the MCC there is the A/C relay and the max speed fan relay.

...Lee

loyd198 · Post by **loyd198** » 17 Oct 2009, 15:46

Ok..I have a 1993 that does NOT have the ECC..its just a manual climate control. The bottom 3 speeds do not work..it only works on high (4). So...now if I could get detailed information as to where the blower motor resistor is ( I guess thats the problem) that would be very helpful. Diagrams and pics would be great ...the more details the better ! I have a 1993 parts car to use for the parts I need. I just need to know exactly where they are so I can get to them. Help me guys before my wife kills me for cooking her on high ! haha

Post by **Ozark Lee** » 17 Oct 2009, 15:58

It is where I told you it was, this is a picture of a ECC system but the location is the same for the MCC.

: DSC02578.JPG (207.96 KiB) Viewed 16753 times

It is the device with the Blue and Black wires plugged into it to the right of the blue A/C relay. Your wire colors will be different on the MCC.

...Lee

loyd198 · Post by **loyd198** » 17 Oct 2009, 16:05

thanks..I was looking right at it and didn't know it ! Does it just push in..or is there any kind of screw or bolt I should be looking for ? Also..are the resistors different for the MCC and the ECC ? If mine doesn't work I'll need to be sure to get the correct one somewhere else . thanks again

Post by **BEJinFbk** » 17 Oct 2009, 17:11

Ozark Lee wrote:The blower motor resistor (or power stage in the case of the ECC) is inset into the air duct directly to the right of the relay(s) that are shown in MIJ's picture. With the ECC there is only the A/C relay, on the MCC there is the A/C relay and the max speed fan relay.

...Lee

The MCC uses simple resistors to vary the voltage to the fan motor for the lower speeds.
The system uses the fan speed switch to select resistors for speeds 1,2 and 3 to that end.
For full speed, the 4th switch position actuates a bypass relay that provides full voltage
to the motor with no resistance.

In the attached diagrams, the MCC control panel is called out as 3/57, the resistor module
as 20/18, the full speed relay as 2/24 and the and the motor itself as 6/28.

94 850 MCC.pdf: (1.17 MiB) Downloaded 2143 times

The ECC uses a "Power Stage" (basically a ECC controlled variable resistor)
to electronically vary the ground to the fan motor for a wide range of fan speeds.
Whole different monkey...They are not interchangable.

loyd198 · Post by **loyd198** » 17 Oct 2009, 20:38

Thanks for the help ! Now I know where to get started at..figures though..my parts car has the ECC..I had forgotten about that ! Oh well, just buy a new one and go from there. At least I still have heat !