84 300SD - Cool AC from front vents, COLD AC from rear vent. Why???

Ok then, I will check behind the glovebox for the defrost actuator on the 300SD.

Thanks to you both for your knowledge. It is greatly appreciated.

Jeff

Oh - I wondered why I didn't have a 300 SD in my 123 Manual.

TIger,

No, the vent positions work normally. No change at different speeds and engine speeds!

Matt

Hev,

WOW! That is one heck of a response! I have been flooded with work this work, but will try this on the upcoming weekend!

You do bring up a very interesting I have forgotten about! I had a similar problem with a 85 300D I sold some time ago and one of the electric actuators was not working; I applied power to each one and you should hear the 'click' when it is activated. One did not and I changed it out and all was well with the system again!

Thanks!

Thanks

I would check the heater monovalve. You might have a leak there. Check the hoses to see if it is warm... the two that goes into the cabin and out. If it is warm, then you got a leaky monovalve.