87 300D climate control intermittent inoperative

[smorelen]

I have an '87 300D whose climate control system has a weird latch-up problem:
- start car cold from overnight rest ( outside temp less than approx 65 F )
-user has no control over system operation..system delivers full-hot air via outboard dash vents, blower does not run. Air movement from vents is due only to movement of car..stop car at traffic light, air movement ceases.
-after driving approx 5 minutes, turn off engine and restart, system now normally controllable, blower runs.
-after the restart, sporadic relay cycling can be heard in dash cavity..diminishes with time as car temperature increases.

If the overnight outside air temp is above approx 65 F, problem does not occur.
Anyone seen this problem?