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...