2000 v70 Blower Motor/Resistor Question

geoffmorrow · Post by **geoffmorrow** » 07 Jan 2011, 19:02

Hello all,

I've been searching MVS for this exact problem, but haven't seen it addressed. I replaced my blower motor and resistor - with the help and encouragement of other MVS members - with used ones about 1 1/2 yrs. ago, and all was well. Now just when it gets cold here in New York, poof, no blower motor. So at this point I've been driving around freezing, with only the heat that comes through when I'm doing 60-70.

My mechanic - Mickey's Automotive in sleep Hollow, NY (great guys!) - was kind enough to test my old motor - which I still have - and it seems to work, though not great. This is kind of surprising since when it "went" before, it seemed to die slowly over several days. So we plugged in the old motor (didn't mount it) and - nothing. So he checked to see if it's getting power, and it seems to NOT be. So then we plugged in the old resistor, and still nothing, and no power to the motor. This was all pretty easy to do since I never replaced the panels or glove box from last time. BTW, I am getting the blinking lights on the ECC (this v70 has the auto setting.) Is it possible that my second resistor is blown? Should I check something else before getting a new resistor? Could it be as simple as a fuse? I happen to have an ECC that I could try. Also, when it "went" this time, there were no last gasps, it just didn't work one day.

Any advice on this would be greatly appreciated. There are many cold days ahead! Thanks!

dj5150 · Post by **dj5150** » 07 Jan 2011, 20:52

did you check the temp sensor? blow it out with compressed air? btw my blower and resistor went out together,

geoffmorrow · Post by **geoffmorrow** » 08 Jan 2011, 09:35

Thanks DJ, no I didn't. I don't where I would find that (searches come up 0), but I'll dig around the site some more and see if I can figure it out. Thanks again.
Geoff

Post by **jimmy57** » 08 Jan 2011, 13:51

On ECC the transistor power stage (referred to as resistor) will shut off blower if the starting current is too high. Tight dry bushings in the motor will cause this. Before you spend any real money, disconnect battery and then remove blower and use WD-40 or other spray lube and spray into ends of motor. There is a vent opening on bottom end that gives access and the openings under blower wheel are access to the other end. The power stages do fail but they are forgiving but the ECC has to reset and battery disconnect might do that for you. The power stage is powered up all the time and does not go off with key so to assure that is powers down and will attempt blower start again disconnect battery.

geoffmorrow · Post by **geoffmorrow** » 08 Jan 2011, 14:47

jimmy57 wrote:On ECC the transistor power stage (referred to as resistor) will shut off blower if the starting current is too high. Tight dry bushings in the motor will cause this. Before you spend any real money, disconnect battery and then remove blower and use WD-40 or other spray lube and spray into ends of motor. There is a vent opening on bottom end that gives access and the openings under blower wheel are access to the other end. The power stages do fail but they are forgiving but the ECC has to reset and battery disconnect might do that for you. The power stage is powered up all the time and does not go off with key so to assure that is powers down and will attempt blower start again disconnect battery.

Thanks for all the info Jimmy, it's all new to me and I can certainly try it. I'm wondering though, when this happens - blower motor shutting off - does it trip the power to the motor off, like a circuit breaker. I'm wondering because we did unplug the motor and test for current. It seemed to not be getting any. Thanks again.
Geoff

Post by **jimmy57** » 08 Jan 2011, 21:11

The power stage is a transistor circuit and the current to blower (voltage level to blower) is controlled by the ECC control unit. On the first start command to power stage to turn on current to blower there is a diagnostic check and if load is excessive the ECC unit will stop commanding the power stage so there will be no voltage if you check between the two wires to blower. The control is of the ground to blower 12V power supply should be there all the time. The ECC has memory of the fault and will attempt again after a lengthy power down or after 5 minutes of battery disconnect.
The power stage can fail and will not regulate current to blower even with command signal from ECC unit. IF there is no 12V supply then check the fuse. I can't recite the fuse number so you will have to look on fusebox cover.

geoffmorrow · Post by **geoffmorrow** » 09 Jan 2011, 10:25

Thanks again Jimmy, I really appreciate it, and that gives me a lot to investigate. Like most things Volvo, it's a complex chain. I'll have a go at it, and post the results. Wish me luck!

geoffmorrow · Post by **geoffmorrow** » 10 Jan 2011, 08:36

Okay, pulled the motor, and got a surprise - a plastic bag had gotten into the motor and was all wound around the spindle. Unfortunately, even after removing all the plastic and resetting the codes (via battery disconnect), still nothing. Going to keep after it, it's COLD here.

Post by **jblackburn** » 10 Jan 2011, 08:51

The ECC unit will remember codes forever, even after disconnecting the battery cable. That procedure may reset it so it tries again, however - how long did you leave the cable disconnected for? I generally disconnect the cable and push on the brake pedal a few times to drain the charge.

Before you reconnect it, make sure your ignition key is in Position II.

Plastic bag? Sounds like you need an air filter in there:
http://www.fcpgroton.com/product-exec/p ... 98-2000%29

geoffmorrow · Post by **geoffmorrow** » 10 Jan 2011, 13:19

Thanks J.A., much appreciated. I had the battery off for a good while as I mounted the motor back, and it did sound like it was trying again. Last time this happened, I got a used motor and resistor and that did it. One of the fine retailers who have a banner on MVS - Erie - had them both, so I ordered them, for better or worse. I'll check back in when I get them in there. Thanks for air filter tip and link, I will be getting that too!