'01 S60:blower motor or resistor?

[paul1149]

Hi,

My '01 S60's blower stopped working suddenly. Over on this excellent thread I got some information on how to take down the blower motor assembly.

I've now got it apart, but have run into some weird behavior in trying to diagnose the problem. There are four wires to the whole assembly - red, black, blue and yellow. The red and black are heavy feeds, and the red is always hot. But when I test the two prongs coming out of the blower resistor and going directly to the motor, one leg is always hot as well. I expected some switching to happen in the resistor so the motor wouldn't always see one hot leg. The resistor is sealed so I presume I can't get into it.

So I'm confused how to pinpoint the problem. One alternative is to replace both resistor and motor. The bottom of the motor housing has some water stains. I have a simple two zone manual control, so no ECC enters into the picture.

Does anyone know a way to test which unit is faulty? Thanks!

[DGM]

If you want to test the motor 6/28 you can connect it directly to a battery. Secure it in a vise before and with 2 jumper wires you can make it run. It will give you a good indication of its condition. At high mileage the brushes wear out. These motors are sealed and aren't servicable. You can lube lightly the bushing ends but that's about it in term of maintenance.

Generally when the power module 4/31 becomes defective, the motor runs full speed. They are normally changed in pair because a bad motor drawing too much current can ruined the power module. Some have reported your situation where they have a silent fail. Note that the power module is now transistorized.

Some elect to change their motor sooner because they have become noisy on start up or when they run. In these cases only the motor is replaced.

Make sure the fuse 11C/26 is in good condition. Probe the A2 and A4 contacts with your multimeter to confirm that you have power at the plug. If your motor run when connected directly then it would most likely be the power module. This module is connected to the CCM 3/112 and controled by it. I am not aware of any test you can performed on this leg.

Volvo has propriatory codes that can be access with Vida-Dice to help in the sectionalization.

Find what I think is the electrical diagram for your climate control.

MCC diagram

Hopes this will help in your repair.

[paul1149]

Wow, thanks an awful lot for all that work. I did order a used motor/blower/resistor, but I was really shooting blind, as I don't understand that voltage situation. Tomorrow, when my eyes aren't so blurry, I'll look over this post more carefully, and then get back.

Thanks again.

[paul1149]

Ok, I've looked at that diagram, and I'm unable to make too much out of it. I think I will wait for the replacement blower and see how that goes. I'm still puzzled why I get 12V at the motor terminal with everything shut off. Hopefully things will be simple.

Will get back.

Thanks again.
p.

[paul1149]

Ok, the used replacement blower/motor/resistor came today. I plugged it in quickly and it seems to work fine. So for $70 I think I'm out of the woods on this, thank God. I'll oil the bearings before I put it in and hope for long life.

Thanks much for your help!

p.