I am certain I have seen the answer to this question someplace, but the search did not turn up my problem.

The car is a 1989 560SEL, with 139K miles. In the brisk Florida winter today, (50 degrees), my heat will only blow through the defroster vents on the windshield. This is with the temp wheel set on hot, and the "econ" button pushed, fan on high speed. With the fan on low or Auto, I get no fan. I flipped around the buttons, hoping it would fix itself, but no.

As a side note, I left the lights on at work the other day and found my battery completely dead. Door locks wouldn't even open. I jumped the car and thought I was ok. Could there be something similar to the dreaded OVP in the climate control circuit?

I appreciate any help you can throw out there. Thanks!

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1989 560SEL (172k)
1989 325IC (122K)
2004 Suzuki Volusia LE (3500 miles)
2005 Yamaha Road Star (20 K miles)