It seems as though everyone has had problems with the stock fan in the Volvo heater.

I have rebuilt the original motor, only to have it squeal like a stuck pig. I turned out that the bushings were worn too badly to use with the heavy steel fan.

Then I installed a plastic squirrel cage fan, which was quieter, but hardly moved any air. Giving up on the stock unit, I took apart a good fan/cage from a Datsun pickup that was out behind the shop, only to find that it had only one speed, which was SLOW. Then it froze up.

In the end, I took out the motor and fan, and capped the hole with a new piece of sheet metal. A little gloss black paint, and you'd hardly guess there was ever a fan there!

Shopping around for a different type of fan, which would be easier to install, service, and replace if needed, I came up with a tube-type blower for a NASCAR setup. It is designed to duct air to the brakes for better cooling.

The tube housing is 4 inches diameter at one end, and 3 inches diameter at the other. The 3-inch end could be cut off so both ends would be 4 inches, but I found that having the 3-inch intake was just right.

My car has a plastic radiator overflow bottle in the left inner fender, so I had to relocate that to the right fender liner. That freed up enough room to attach a 4" metal flex duct to the intake of the heater, and then attach it to the 4" end of the blower. I temporarily secured the blower to the fender liner with some zip ties - I'll fabricate a nice bracket later - and hooked some 3" flexible metal duct to the small end, and ran that forward to the stock fresh air intake spot to the left of the radiator.

Originally, the blower was meant to draw air through the 4" end and blow it out the 3" end - increasing its velocity. By simply switching the + and - wires, the fan now runs in reverse. I put terminals on the wires and plugged them right into the stock fan wiring, so the fan switch works.

So, now I have a blower that's absolutely silent, and although it runs at only one speed, it puts out enough air to quickly clear the windshield.

If I took the trouble to cover the blower with the 4" tubing, you couldn't tell there is a blower in there!

Pictures to come...

Wow,
what an effort. I did the 73 blazer fan conversion with a spare plastic 122 fan. It is one speed but very quiet and much faster at defrosting. Looks almost stock to the untrained, only took one extra hole drilled in the old housing to make it fit.
Looking forward to seeing your photos.
-Erik

Lots of effort. I just got my new (old) squirrel cage from Jim and drilled out the shaft hole to fit my 3 speed 1987 S10 blower motor. Put a small piece of 1/4" plywood down in the housing hole and set the squirrel cage down in position. It rests on the plywood which gave me plenty of clearance then measured from the housings motor mounting face to the bottom of the S10 mounting flange. Made me a plywood spacer, removed the plywood from the housing hole and primed and painted the new spacer and now have a relatively quiet fan.

Best
Ray J.

There are endless ways to repair/replace the stock blower fan. I may decide to change the setup I just installed, but for now it's easy, clean, cheap and effective.

Basically, I just removed the old fan, covered up the hole, and put the new fan inline in the intake hose. I could have left the old fan in place and no one would realize I had even put in a new fan. :-)

Now that I think of it, I have a second fan, exactly like the first (two front brakes on a NASCAR) so I could put the second one in line with the first and have two speeds...

I would love to see pictures of this installation. As most, my fan is noisy, moves little air and the squirrel cage has been bent so doesn't rotate smoothly any more.
Dennis

Sorry, been in Las Vegas for a week. Home again, home again!

Tomorrow (Thursday) I get to dig the Volvo out of the pack of vehicles clogging my driveway and get back to work on her.

As far as photos go, I think I should start out with a panoramic picture of the parts of my current vehicle collection that are here fore the moment.

I also want to post some pix of the flex fan installation; it's nearly done too. I only have the radiator overflow and windshield washer tanks to mount.