I blower motor works fine..There seems to be power to the switch,BUT none of the speeds work at all.Any idea what could cause this?some times it starts up & will work for a few hours ?then just die,, no fan...

I also wonder,at some point the MCC was clicking when I moved from 1- 5 at each point,,is there any significance when it seems that the clicking stops & goes away???

Dear Blindboy,

Hope you're well. Yes! The motor's speed control switch depends on a resistor, mounted in the air duct near the motor. This is Volvo part #6848756.

This item no longer is available from Volvo, see: https://www.tascaparts.com/oem-parts/volvo-resistor-6848756 .

Happily, this resistor can be had at: https://www.ipdusa.com/products/10346/121735-blower-motor-resistor-manual-climate-control .

Hope this helps.

Yours faithfully,

Spook

I have 11.78 volts at the plug for the motor,,& yet it doesnt spin there??

Is the plug for the motor making good contact with the motor? Maybe bend the contacts together a little. Also, wiggle the plug to see if the motor will run when it isn't running.
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Mine:3-940s running, 1-740, 2-940 parts, dtrs:4-940s running

if you have 11.78 at the motor and the ground for the motor is ok, then you need a motor. good luck, chuck.

the motor is fine, The resistor tests for proper resistance,,must be the ac controls...Ill try to figure out how to test it.
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direct wired it at the battery & it spun fine..

Cant find a replacement anywhere,tried 2 junkyard pieces..no good.Has anyone jury rigged resistors to replace it??

but I wonder if there s a way of testing it to make sure its the problem???

How can you tell if its working or not?

Dear Blindboy,

Hope you're well. If moving the speed control has no effect - i.e., if fan speed does not change - then the resistor has failed.

Hope this helps.

Yours faithfully,

Spook

The resistor is not in the circuit when the speed switch is on the highest speed (all the way clockwise). So, if the fan works when the switch is on high but not on any other speeds, the resistor pack is probably bad.
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Mine:3-940s running, 1-740, 2-940 parts, dtrs:3-940s running

Im trying to sand down the contacts on the pack.I think they maybe corroded!!??