My blower only works on speeds 3 and 4, nothing happens when I turn the knob to 1 or 2. Is this more likely to be the switch, the resistor, or something else?

Where on the car is the resistor, anyway?

Thanks!

It is likely the motor.

But, if you continue to run it on anything but 4, you'll need a new resistor too.

Here are photos of the resistor, and an example of one where the above advice was not in time. http://cleanflametrap.com/fan.html

Post the year of your 240 for more specific help.
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Art Benstein near Baltimore

Ugh, that's what I was afraid of.

The car is a 91 240 SE. Is there anyway around pulling it all apart and replacing the motor and the resistor? That's not a job I'm looking forward to.

Don Foster's chainsaw message requires much less disassemble. I would argue that it is faster for the novice but many would argue that it is not worth the slightly reduced airflow. It also offends the sensibilities of those who like things done "right". I also fully believe those that claim once you have done two or three the right way, it is just as fast as the chainsaw method.

Mike

Thanks, I think I'm going to give this a shot and cross my fingers:
http://wagonmeister.com/19.html

Yeah, this is a newer twist on the chainsaw method. Removing drivers seat is about essential and the passenger. Make sure you hook up you motor turning the right direction and test it BEFORE getting very far along. It is not uncommon to swap the wires and you can't really trust any of the color coding on the new motor's wires.

Mike

Art, it is my understanding that the newer blower motors (post 80?) rely on resistance to lower speed whereas the older ones reduced speed through taps off the windings.
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1980 245 Canadian B21A with SU carb but electronic ignition and M46 trans in Brampton, Ont.

Yeah, by my experience and study of the green books, the permanent magnet motor was introduced to Canada and US markets in 1981. That is the year the resistor was first used.
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Art Benstein near Baltimore

The math professor went crazy with the blackboard; he did a number on it.

That is why I'm wondering why you think it is the motor rather than the resistor. I'm thinking positions 1 and 2 are burnt out on the resistor whereas 3 and 4 remain good.

If the motor isn't squealing, I wouldn't buy a replacement until I pulled the resistor and measured for continuity. Might even be able to test at the switch before opening the blower. And one might be able to replace 1 and 2 with individual resistors.
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1980 245 Canadian B21A with SU carb but electronic ignition and M46 trans in Brampton, Ont.

That is why I'm wondering why you think it is the motor rather than the resistor.

To put it simply, the only thing that will cause the original resistor to go is a motor that is drawing too much current. The increased power consumption is not necessarily converted to noise until it is too late to save the resistor.

As the bushings gum up and keep the motor from starting easily, the resistor sees locked rotor current for increasingly longer times until it overheats (with no cooling) and opens. In any switch position other than off or 4, the motor and resistor have their fates inextricably entwined, and it is always the motor's fault.
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Art Benstein near Baltimore

Colt: The original point and click interface.

I had the exact same issue and finally she died. I just finished a 7 hour day of installing one and had a ringer with me to do so. I went for everything from the motor to the resistor to the switch. Phew!

It's probably the resistor, which is a pain to access.

The reason it is placed in the air stream within the housing is because it adjusts motor speed downward through resistance, so needs cooling.

The lower speeds require more resistance, heat up and often burn out. Leaving the higher speeds operating because they don't require as much resistance to achieve their speeds.
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1980 245 Canadian B21A with SU carb but electronic ignition and M46 trans in Brampton, Ont.

All you mentioned could be a problem but the switch is the only thing easy to access.

The resistor comes mounted with the motor in the air stream inside the housing. They are rugged but I have no experience with one that has failed to give a reason either way.

If the motor runs smooth on the other speeds then you might be looking at a bad switch contact or wires to different sections on the resistor that govern the speeds.

Phil