Hi all.. Im just purchased another C280. Its a 99 and Im trying to fix a few items. But currently, its cold and I need heat thru the center vents...

The Climate Control will NOT allow selection of the center vents. When I depress the selector button, it allows upper & lower arrows only. How do I select the middle arrow for the center vents. Currently, I have no air from the center vents.

I have not pulled the control valve to test the vacuum elements yet. Hoping that I dont have leaking elements..
I replaced the elements on my 95 C280 and it was a pain... Will the 99 C280 climate control unit block out a selection if the element(s) are bad??

Thanks for any assistance here..