91 mercedes benz 350sd turbo air conditioning set on center vents comes on about two minuter the most ,and then directs all air to the windshield .was told the push button controler bad then was told a,c actuators leaking . we checked one by one with a vacuun gauge and heard all actuators working , need help very tough problem .ps and very expensive unit . 700dollars

Vacuum pulls the center vent open & the SAME vacuum line goes to & closes the defroster flap. LOSS of vacuum to those elements are a starting point!

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

those center vents are confusing. read your owners manual. sometimes they come on, sometimes not. they supply only outside air.

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71 220D 169K wrecked
83 240D 118K sweet 4 speed
91 350SDL (one of the 60% good engines) 156K
84 300d (loaner to my sister) 189K
79 300SD (partswagen)
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70 220d (partswagen)
68 280s GASSER!!! under construction now
85 300sd 310K miles winter beater car retired
93 300d 2.5 turbo 168K wife's car
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69 250S newest project 54K