I get no heat by turning the wheel, but if I push the right two buttons at the same time, there is plenty of heat at the defroster outlets. One of the buttons has to be the defroster. The air flow does change so I guess there are some flappers that are working.

I don't feel any heat at the center vents.

These is a new to me, 86 300 SDL.

Thanks for any help, I have searched and read many posts on heater problems but I could not match them to my problem.

Harry

It sounds as if the push button controller is acting up. You may have to replace it so solve the problem.

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

Try resolidering the circuit board in the climate control unit. This solved a simalar problem that i had. a solidering iron and solider is all you need compared to $350+ for a new climate control unit.
hope this helps!
good luck,
Adam

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320