After consulting the manual I learned that air should not be blowing out of the defrost vents in conjunction with the dash vents with the AC on (Normal mode). Funny thing is, when I move the temp. control to warm, the air stops blowing from the defrost vents, even as the Normal button remains engaged.

Is this a simple fix or an expensive job?

Thank you for the advice.

__________________
2004 E320 Wagon
1989 300SE
1998 Range Rover 4.0 SE

You need to perform a vacuum diagnostic routine. This will check for vacuum leaks in the system.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

You probably need several if not all of the vacuum actuators replaced. I have only done it myself, never at a shop so I dont know the costs. The parts for the 7 actuators came to aaaaabout $250. A lot of disassembly to get them installed. The rubber diaphrams develop leaks and the system no longer works.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k