Yes, you are right! It does have something to do with cold temperatures. Cold seems to make the limit switches fail.
Mr. VR-4, your limit switches are exactly why it doesn't work. I've replaced them on 3 occasions, and they keep failing.
My solution is to use an infrared transmitter, which will send a beam of invisible light toward the gear that spins on the motor assembly. The reflected light will be measured by a detector. The "gear" that spins has a notch in it, that moves the limit switches (which keep failing). I'm going to capitalize on this notch. Here's how it works. When the notch passes in front of the beam, it will reduce the amplitude of the light reaching the detector. I will use a comparator chip to activate either a relay, or a transistor switch when a preset threshold is crossed. This will then switch off the motor when it has reached either the upper, or lower limits. Easy money! (I guess if you have a EE degree). I will "pot" the transmitter/detector pair (potting is a substance that you can place electronic parts in and it hardens). I can then drill two holes in it, making this the same size exactly as the factory limit switches.
Whatdayathink??