Windows slow-when cold.

[krjt]

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.