In Reply to: Center Dash Vent installed...easy and cheap! posted by Tim in N. FL on February 04, 2001 at 18:08:38:
I installed a center dash vent (CDV) on my '87 535is over the weekend. Wait a minute...I should say that I made what BMW had already installed at the factory functional by adding two parts. A buddy of mine from NY found the "new" vent plate and the roller knob out of an '84 e28 in the salvage yard and mailed it to me. What a nice guy! Anyway, the rest of the hardware is already in place.
Others on the forum have written about how BMW NA disabled the CDV for the North American market because some owners were confused about the HVAC controls...go figure. I'm not sure when BMW started disabling these vents for the NA market.
Anyway, it was incredibly easy to install...simply take off the old vent plate (2 phillips head screws), unclamp the vent lever (actuator) that BMW retained with a metal clamp, pop-in the roller knob (make sure it is facing the correct way), snap the vent lever (actuator) into to the hole in the knob, install the new vent plate (with the hole for the knob), reinstall 2 screws and voila....you're in business. All in all, a cheap, worthwhile addition to the car.
87 535is 5-speed 152k
(now with top CDV enabled)
The wheel to use center dash vents was installed in US e28 cars thru 1985,maybe some '86's. ALL e28 cars have the vent mechanism installed,but in '86/'87/'88 cars,it's had the wheel and vent with hole for the wheel replaced with a "Vent" that doesn't work,although the flap,arm,etc. are all still under the false "vent". BMW started using a different system to open/close the fresh air system,which is also the a/c outlets.
Many complained also the e28 a/c was poor,and closing off this access meant more cool air always flows from the 4 dash vents.
I find the additional upper dash vent more evenly distributes fresh air and a/c once the car is cool,and have gotten the wheel and wheel-opening vent from earlier wrecks and installed it on 3 of my e28's, including the recent '87 535is.
Just removing the two small phillips screws that hold the front(towards the driver)of the vent,removing it,and looking at a working early e28 system will explain itself well enough to remove the wheel,and add it and the older vent to your later cars for better airflow.Just did mine last week.