This is a follow up to an original post titled: “1992 Volvo 940 Sedan Blower Motor”

My IPD replacement blower motor just totally failed after approximately 5 years of use and 80,000 miles. I replaced the blower motor with another new IPD blower motor. In addition, since the blower motor was not functioning on all speed positions on the fan switch, I replace the blower motor resistor with the correct genuine Volvo blower motor resistor part number. The blower motor and speeds worked perfectly well for approximately one month.

Recently, the blower motor operation has transitioned through various symptoms. To clarify, occasionally it is working on high in all fan switch positions and at times only one fan switch position. It is important to note that at times I would have to hunt to find an off position. Occasionally, I could find an off position, but the off position would be at any fan switch speed location. I have to simply flip the switch to all the positions in hopes of finding one that acts as an off position. Now, I can’t even turn the blower on in any switch position. Is my fan switch now bad, or is the blower motor resistor bad again? If the resistor is bad again after only two months of usage, what is causing the blower motor resistor to go bad? Any thoughts on whether I should replace the fan switch? If so, is this an item I can buy separately at a reasonable price?

 

Is there a blower motor relay or other component that may be contributing to my above problem? I'm hoping someone has some thoughts as to what the root cause may be. Thanks

 

Sounds like it's the switch itself that's bad...

 

assuming this 92 940 has MCC (Manual Climate Control)
no relay. power from battery, through the 'positive terminal' (which is near the steering column under the dash on my 92 740), through the ignition switch...

ignition switch pin X (on in I and II) has a black wire to fuse 16, fuse 16 black wire to a 2 pin connector 'A', black wire to fan control switch pin C-1.

fan switch has 5 outputs, 1 each for settings 1-5, and 1-4 go directly to the fan resistor block (5 goes directly to the motor with no resistor), and from there to the fan via a 2 pin connector N at the motor. the climate control block also has a 'tap' that drives resistor for fan setting '1' so it forces the fan to run on low if the AC is on. the other side of the fan is wired to ground 31/10 at the right A post (near passenger door lower hinge).

from your symptoms, it sure sounds like the fan speed switch is bad.

 

now... if you have the ECC Electronic Climate Control, its all different. this has the temp **** marked in degrees rather than blue-to-red and its fan **** has an 'auto' setting.

the ECC controls the fan speed via electronics and has a complicated relay/electronic control block stuffed up behind the glovebox somewhere. the schematic shows no resistor pack on the fan case.

 

'92 940s don't have ECC... The only 940 with an ECC is the '91 SE.

 

well, the greenbook for the 1992 740/940 (not SE) lists it as an option. maybe US models were never equipped with it, we got a rather fixed set of options on our cars here.

the greenbook also shows a heater-only, no AC configuration, who's fan switch works just like the MCC I described above.

I have seen ECC on a 940 (not the SE, which was really a 960 turbo), it was a totally loaded 93 or 94 that had the turbo (but didn't say Turbo on the back), sunroof, leather, power seat, cruise, and about every other option possible, and the headlights with integral fogs. When I first saw this car, I thought it was a 960 but realized it didn't have the alloy hood that covers the wipers, nor the 960 style dashboard.

 

'94 and '95 dropped the TURBO badge.
I may be wrong but I don't believe it is possible to have the ECC in a 940: the whole dash design is different including the sensor integrated in the dash, etc. I know for a fact it was never an option offered in the US... Now, nothing is impossible but of the couple of thousand Volvos that have gone through my hands I have never seen it. I use the hard copy dealership parts catalogs for my references and list it only as version in 1991 which is the SE... Minutia, anyway...

 

the solar sensor is part of the right hand dashboard speaker grill on those, isn't it?

maybe this car I saw was a grey market import or something.

hey, VADIS for a 1994 940 lists two right side dash speakers, one with ECC (3533415), one without (3533385)

it also lists a 940 ECC option, with dashboard control 3537006.

 

Pierce, Thanks for the detailed reply. I will see if I can purchase only the switch and replace. Can you provide any tips on how best to access the switch for removal and replacement?

I will comment that in searching the web for a solution to this problem, I did read that the US 940's did not come with ECC or an ECC option. However, I believe I read ECC was available in Europe. Also, I stumbled upon a website that provided very detailed descriptions and pictures to convert a US 940 from MCC to ECC. It is quite a large undertaking. You will have to google for this site, I didn't book mark it since it was way too much of an undertaking, and I'm currently just trying to get the fan working properly and keep the car running. Pierce and Lev, I appreciate your help!

 

yeah, sorry for the diversion of ECC

VADIS says, the fan switch for a 92 940 is PN 3522577, and it looks to be screwed into the back of the ventilation control panel with a couple torx(?) screws. kinda looks like you need to pull the whole HVAC control panel out to get to it, thats held on with like 4 screws, accessible after you remove the trim panel that goes around it and the couple dashboard switches and ignition key that are between the HVAC controls and the steering column. wild guess says, remove the glovebox first to access the plugs on the back of the HVAC controls?


(HVAC = heating, ventilation, air conditioning... generic term)

 

Pierce, I actually replaced the switch by deflecting the trim ring around the Manual Climate Control (MCC) panel inward toward the switch ***** and gently pulling the trim ring outward. Once the trim ring around the 3 ***** is loose, the switch panel can be removed from the dash.
There are then four screws that must be removed to remove the MCC module. In addition, there are two metal tabs behind the lower two screws and in front of the MCC unit. These can be bent forward and away from the MCC to enable you to pull the MCC out of the dash. Wires are short and connectors must be carefully removed. Also a vacuum line connector must be removed. Then the MCC can be removed and the switch is easily replaced by removing two small screws.
To reinstall, reverse the removal procedure insuring the tabs are bent back and the electrical connectors and vacuum connector are connected.
Replacing the connector resolved my problems and I now have all speeds working well.

Pierce, Thanks for your help!