My 82 3000sd has an off and on problem with the heater fan. It seems to be getting worse and now the fan will rarely run. When it works it works well and sounds fine. I suspect a bad connection in the control buttons. Am I off base here? And how does one remove the console to reach said buttons?

 

I had the same problem with my 2001 S500, the heat and ac were "on and functioning" but there was no fan. Sometimes it worked but got worse and worse until it never came on.

The fix was about 700.00 covered under an extended warrantee for me. I had the fan and fan controller replaced. Apperently the fan controller goes out but they are one unit sold that way. (My fan had a wierd squeak anyway.) Good luck with it.