Hello all,

I have searched and read many forums trying to find the answer to my dilemma, but no answers so here goes the post.

The car in question is my wifes 93 300D.
The problem: About two maybe three weeks ago the heater started blowing cold air on the passenger side, but warm in the driver side. This issue affected both the center lower console vent (near knees) and the outer vent (near window). Then before I had the time to take a look at what was going on, the problem switched sides (right to left).

Now it has changed again, in that 1/2 half the car is cold the other hot, by that I mean that even in defrost the left vent blows cold, the right hot. When the switch is set to cabin recirculate the center 2 vents do not blow at all and I have cold on upper, left and lower vents on driver side and hot on upper right and lower vents of the passenger side.

Now before anyone asks the car does not have dual side climate controls.

Can any kind soul please tell me if my 'computer malfunction' guess is correct or could there be a simpler answer. I don't think any of the pods are at fault since the problem simply switched sides and I don't think the monovalve is even in the picture since I am getting heat on one side.

Please help a severely puzzled individual.

Adriano

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Adriano

83 300SD 500,300 miles (Well seasoned work horse AKA "Put Put")
93 300D 245,000 miles (Moms Baby AKA "Sweat Pea")
87 300D 185,000 miles (Life giver, aka parts car for my 300SD)

More info

After several cuts an bruises taking part of the dash apart (was quite concern taking the passenger airbag unit out (never removed one before).

Manifold input is 15Hg of vacuum.

The selector switch has no effect going from defrost to recirculate causes the flow to remain the same. Left cold right hot.

But what I have noticed is that now it is stuck in a somewhat weird state. By that I mean that air is blowing from the defrost cawling, the lower and side vents and will not change.

Have wiggled all the fuses in the fuse box, checked as many connections as I can without taking the rest of the dash apart. The pipe bringing in the coolant from the engine compartment is very hot telling me the monovalve is operating as it supposed to for maximum heat call.

Any ideas?

Thanks.

__________________
Adriano

83 300SD 500,300 miles (Well seasoned work horse AKA "Put Put")
93 300D 245,000 miles (Moms Baby AKA "Sweat Pea")
87 300D 185,000 miles (Life giver, aka parts car for my 300SD)