89 300E

Whenever it gets cold, my windows move up and down at a snails pace until the temp. warms up. Where should I start, the switch, window regulator greasing, the motor or electrical resistance due to age? Since it reacts differently due to temperature, I thought it might be the parts inside the door, but the switch gets heat from the exhaust too. Any advise?

Thanks.

W124 owners who take the time to remove the door panels and lubricate the sliding jaws and other friction surfaces of the regulators will be rewarded with far fewer window problems in the long run. MB sunroof paste works well.