300TE A/C Question

[BENZ-LGB]

I recently bought a 1989 300TE for my teen daughter. The car is in A-1 shape. I do have a question regarding the operation of the A/C which maybe other 300E or 300TE can help me with. (The info is not covered by the Owner's Manual)

When the system is set to the EC or A/C settings I do not get air coming from the center dash vents until one of two things happens:

1. The outside tenperature is above a certain point (usually over 65 degrees), or

2. I set the temperature wheel to its minimum (coldest) setting.

I do not get air from the center vents until after either 1 or 2, happen.

Otherwise the A/C and the heater work very well.

The A/C in my 1991 420SEL works differently. I can get air out of the center vents under almost any setting (except heater mode).

Thanks for your help