The Stovebolt Site Forums The Shop Area The Electrical Bay Better Heater Motor Fan?

It's the time of year when I always think of this. Is there any replacement heater motor squirrel-cage fan that will push more air in my '48?

It blows OK on the floor but when switched to defroster mode, it's not so hot.

Thanks!

Wally,

I refurbished my Harrison heater and blower motor based on a process outlined by Deve and I'm quite satisfied with the results. The heater has a 12V blower motor and a DC motor contoller with a potentiometer that gives me infinite fan speed control as opposed to high/low. Here's a link or two for your reading pleasure:

Heater Restore

12V Upgrade

Let me know if you have any questions, good luck!

Keep in mind that on the defroster setting it has to blow through the hoses up to the vents. If the hoses aren't in great condition the warm air escapes through the cracks and holes, or stops if they're kinked.

Also, the trim strip around your front windows should have a small piece of rubber on the inside, on each side of the defrost register, to keep the defrost air from escaping sideways along the window trim.... these little chunks of rubber keep all the air directed onto the window...

Here’s a thread I did about replacement motors.
https://www.stovebolt.com/ubbthread...motor-replacements-napa.html#Post1136055

What temp thermostat you using? A 160 or 180 may not cut it in Montana. Maybe switch to a 195 over winter. Another trick I have used in a vehicle where the heater just could not quite do the job is to cover the radiator with cardboard. You will notice that semi trucks cover their radiators during winter . You do have to be very observant when you are driving during a warm snap so as to not overheat the engine.

Well Wally, me old Stovebolt taint as fancy as yours, still the same old original 216 with
the same old 6v electrical system.
I did rebuild the heater motor when I restored the original deluxe heater, i.e., turned the
commutator, new brushes and bushings. Fan runs fine, will blow papers or rags around the
floor in front of the duct, the defrost hoses are new and tight, and I had the defrost funnels
out and reinstalled, (correctly). Been running a 180° stat year round for 12 years now.
The Engine stays cool in the summer heat and plenty of heat in the winter cold.
Once she's warmed up I can drive without a coat or gloves and that's saying something
for an old dude like me with poor circulation in his mitts.
I drive her regularly in the cold weather, as long as there isn't snow, slush or rain for the day.
When switching over to the defrosters the air can barely be felt at the windshield.
I've always felt there should be more air but short of redesigning the blower for more output,
I think that's the way they were from the factory beck in the day.
Denny Graham
Sandwich, IL

Too much air to the windshield may not be a good thing under certain weather conditions. We have a lot of humidity around here. Defrosting and defogging are two very dissimilar circumstances.
I have a motor which can be wired for really fast or not so fast. When I first set it up, I had it wired for really fast.
On a humid, rainy day, that fast blowing fan may as well have blown a constant spray of water on the inside of the windshield (even at the low speed setting of the Harrison toggle switch).
I rewired it for the slower speed and had much less trouble with the a wet windshield.
Just like so many other mechanisms on these old trucks, the engineers always seem to do things for very real purposes.
Carl

Thanks for the link to the 12v motor upgrade. Added to the list!

Little off the beaten path here but what a great bunch of old 40's and 50's pictures of general motors trucks with those 6 cylinders. Ill bet there has been Mulie or two on the back of that there 48'.? Great scrap book..

Love the history Wally! Reminds of when I hand drilled a new hole in the head of a SBC for a new alternator bolt. All done in the backwoods of a New York forest with a bolt found in my emergency Tupperware bin in the trunk of my 54 Chevy 4-dr sedan. I wish I had more photos to document it all like you did.