weak heater blower

[am99ey]

Hello
Now the weather changes to cooler and my screen is fogging over occasionally again. Switching on the blower/heater just barely gets the screen demisted.
The air stream towards the screen is very weak. The lever on the dashboard to car/screen works and redirects the (weak) stream. The noise of the blower can be heard clearly.
My question: does this motor get tired with the time? What is the correct rpm, and how to measure/determine.
Can the blower be rebuild to become strong again ?
Where should I start to check before I tear down the assembly.
Thanks for ideas, Andy

 

[volvoguys]

It's not uncommon for the blower motor bearings to bind up over time due to use (or lack of use). With 2-speed motors, like in your SV, the problems typically begin with the low-speed operating slowly until it stops working and the high-speed being used instead. It'll eventually stop, too.

I have fully functioning single- and 2-speed motor assemblies that have been bench tested (on both speeds) for 10 minutes and run quietly without getting hot. I've already disassembled them and removed buildup from the impellers and housing so they're ready to bolt on.

PM if interested.

 

[alpine_64]

Hello
Now the weather changes to cooler and my screen is fogging over occasionally again. Switching on the blower/heater just barely gets the screen demisted.
The air stream towards the screen is very weak. The lever on the dashboard to car/screen works and redirects the (weak) stream. The noise of the blower can be heard clearly.
My question: does this motor get tired with the time? What is the correct rpm, and how to measure/determine.
Can the blower be rebuild to become strong again ?
Where should I start to check before I tear down the assembly.
Thanks for ideas, Andy

As Mark mentioned they get clogged as the grease gets thicker and embedded with debris so they slow down and actually put stress on the motors.

If disabled and cleaned they work fine.. iirc some people lived them with white lithium grease.

Also make sure the hoses to the screen vents haven't got any cracks, are sealed to the outlet and vents completely and that the seals in the defector of the heater box are all good.

 

[Thor 1211]

Hello
Now the weather changes to cooler and my screen is fogging over occasionally again. Switching on the blower/heater just barely gets the screen demisted.
The air stream towards the screen is very weak. The lever on the dashboard to car/screen works and redirects the (weak) stream. The noise of the blower can be heard clearly.
My question: does this motor get tired with the time? What is the correct rpm, and how to measure/determine.
Can the blower be rebuild to become strong again ?
Where should I start to check before I tear down the assembly.
Thanks for ideas, Andy

In a 1960 review of the new Sunbeam Alpine in Popular Mechanics, Tom MacHill said that the heater blower in the car was like "a mouse blowing on your foot". That has been my experience and unlike Mark and Mike I think the fan is, in a word, pathetic and never did work fine but I guess it's possible that some are better than others. My next project is to get a Ford (or Chev) fan motor and try to mount it in place of the stock unit.

 

[volvoguys]

The early production Series Alpines were fitted with single-speed blower motors and, frankly, when I bench them, I find them to be a little lackluster and unproductive. Rootes eventually changed the blowers to 2-speed, and I find the high speed more than ample to demist my screen and throw heat on the floor. Now, I don't know how it would work on a 20° winter day with ice on the windscreen.

The upgrade consisted only of a large ballast resistor and second main lead. But the blower housing and mounting bracket is identical so a 2-speed can be easily added to an early car by wiring a 2-position switch.

 

[Beamin]

Dont forget to check the intake screen. 55+ years of leaves, rodent nests and other debris can effectively block all airflow through the blower housing.