N00b 101: Blower quit on 99 V70R

Post by **volare** » 29 Jun 2016, 21:46

I've been surfing around the forum reading similar topics; through what I've gleaned there I've gotten as far as removing the blower motor. It worked back in the winter when I bought it, plenty of heat. It's my daughter's car so I don't know when it crapped out but it had to be recent; she told me the AC wasn't working so I checked it and nada, zip, nuffin, no air at all hot or cold.

No red blinking trouble lights, I can hear the various doors in the vents moving when I switch them around on the dial, and there's a faint hum or buzz from somewhere within when I try to turn it on. Does not work on auto or manual fan setting. Can hear the AC compressor/clutch cycle when turned on. No blown fuses. Did try the paperclip trick to the power wires, no joy.

Pulled the blower motor, very easy to access on this vehicle, and upon inspection while the multimeter confirmed it has electrical continuity I haven't checked it by direct wire, and there is a spectacular amount of crumbly black crud plastered all over the back of it and even more visible and falling out from inside when I tapped it. Squirrel cage does spin by hand with a soft but audible squeal. Am I safe in assuming that the motor is indeed shot and all the skidge is the sad remnants of the innards?

If so, do I even bother hitting up the boneyard given the model year or am I better off ordering new?
Thanks for putting up with a Volvo noobie!

Post by **scot850** » 29 Jun 2016, 23:11

If you have movement of the cage with the shaft in the direction of the shaft it is a good chance the bearings are worn out. Many cars of that age have had the motors replaced by now, so at a boneyard you may find a good one. I check for play in the shaft and how easy the cage spins. If they seem ok, then chances are it's good. A little light oil on the bearings and see if it spins up. If the same thing happens in both Auto and manual speed control it may be the resistor pack that has failed.

Last but not least, also check fuses and clean out the cabin temp sensor in the dash to the left of the ECC control unit and behind a little grille in the dash.

Neil.

Post by **Ozark Lee** » 30 Jun 2016, 04:51

Based on the description I think Neil pretty much called it. What usually happens is that the bearings on the blower, which are just a brass bushing, dry out and the motor winds up drawing too much current and it takes out the power stage (the ECC version of the blower resistor). The power stage is an expensive little critter and what you don't want to do is replace the power stage and then have the bad blower take out the new one. Sometimes you can save the old blower with oil.

I use Tri-Flow oil that has an extension tube that lets you put the oil right on the bearing through the squirrel cage and then I hook the blower up to a battery and run it both forward and backwards to work the oil down into the bearings. The rear bearing is easy but the front one is tough to get to without the extension tube.

...Lee

Post by **volare** » 30 Jun 2016, 06:21

scot850 wrote:Last but not least, also check fuses and clean out the cabin temp sensor in the dash to the left of the ECC control unit and behind a little grille in the dash.

Stuff I looked at prior to pulling blower:
Did pull the pertinent fuses to check, all seems fine there.
Per other threads I hit the cabin temp sensor with some compressed air thru the grille; is it worth trying to get at the sensor for a more thorough cleaning or would the previous have been sufficient?

Ozark Lee wrote:I use Tri-Flow oil that has an extension tube that lets you put the oil right on the bearing through the squirrel cage and then I hook the blower up to a battery and run it both forward and backwards to work the oil down into the bearings. The rear bearing is easy but the front one is tough to get to without the extension tube.

If I lube it, run it off the battery and it works, I assume re-install and test, and if it still won't come on, that tells me the power stage is shot?

Thanks to you both!

Post by **Ozark Lee** » 30 Jun 2016, 07:15

volare wrote:
If I lube it, run it off the battery and it works, I assume re-install and test, and if it still won't come on, that tells me the power stage is shot?

Pretty much. The control head could have some issues but based on the squeaky bearings the typical scenario is that the the power stage gets cooked by the excessive current draw from the dragging blower motor.

...Lee

Post by **scot850** » 30 Jun 2016, 08:34

+ 1 with Lee. Blowing the cabin sensor out with compressed air isn't really effective. It is a pain to remove if you haven't done one before, but quick once you know. I did a write up on this sometime ago. Requires removing the radio (check you have the code), removing the ECC unit and then feeling in behind for the 2 push in tabs toward the front of the controller to remove. Looking from the front, one is at about 4 o'clock and the other at about 10 pm if I recall correctly. Remove the wire connector first. WARNING: There is a rubber seal at the front of the cabin sensor that may stick on place, or if you are un-lucky will fall down inside the dashboard!!

Neil.

Post by **volare** » 01 Jul 2016, 10:02

Update:
Thanks again you guys, it's much appreciated!

So upon direct powering the blower, it either doesn't do anything OR it starts spinning at speeds that vary from high to low with no discernible pattern or reason, eventually slows and stops altogether and won't start again. Far as I know it should start spinning at high speed and stay that way?

It appears to be the original unit for the vehicle, AC Delco. Local parts place quoted me $105 for a new one.
Boneyard next.

Going to clean the sensor while I've got the thing apart anyway. Do have the radio code.

Post by **Ozark Lee** » 01 Jul 2016, 11:56

If you can find a power stage at the boneyard go for that as well. I think I paid around $125.00 for the last new powerstage I bought for an 850.

...Lee

Post by **volare** » 01 Jul 2016, 18:47

VICTORY!

I wandered the boneyard and found a '99 V70XC amongst all the 850s, in quite decent shape (which I shall be returning to for more bits and bobs), which yielded both the power stage and blower I needed. $40 total and all is copacetic. AC blowing nice and chilly!

I don't know if the power stage I took out of mine is any good but judging by your advice it made sense to replace it either way.

I did lube the 'new' motor before installing it as well. Gave the AC a bit of charge from a can of PAG oil/dye and the gauge reads comfortably in the green. Waiting for dark to go see if there's leakage anywhere with the UV light just in case.
Thank you to all of you for the wisdom!

Post by **scot850** » 01 Jul 2016, 23:10

Glad it all worked out and well done!

Neil.