Is there another "pod" that controls the blending of the air? That is to say, is there a pod that controls the cool/hot air mixture flap....if so does anyone know where its located on a 300SD (1984 W126).


Its NOT the monovalve, as I've already changed that and it is energizing properly.

It can't be in the control units, as I've swapped everything iwth the other car, and the other car

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1) 84 300SD 285K+ Miles (Ver Calif)
2) 84 300SD 175K+ Miles (Ver Federal)

There's a diverter flap but I'm not sure exactly where it is (it's been a while). I think it's on the left side of the console.

You might have a bad cabin temp sensor or a tired aspirator blower. Make sure the sensor and the hose from the sensor to the aspirator motor are free of blockage. I can get the temp-to-resistance test specs later.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

I don't know if you've tried this, you may wanna change out the ACC pb panel -- it's not very difficult (just have to remove ashtray, and radio).

I had this problem also ('86 W126)and was told that the pb units go bad though the years. They are very expensive, but i found a place that will give you a remanufactured/refurb for $155 plus shipping and core charge of $75. It also comes with a 3 year warranty and looked brand new!!!

my cold A/C would only go through the defrost vents and was pretty much useless, esp. since i live in Phoenix, AZ!! Now, the new pb works great and so does my AC.

If you want the name of the company PM me. I'm not sure if URLs/links are allowed here.

R@Z

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R@Z()R

1986 560 SEL

actually just changed the ACC PB unit about 1 month ago as part of this initial workup....

It wasn't the problem...well, at least I have a new PB unit.

This problem is really strange, I just get about 10 seconds of hot air at the start (especially if you went to a store and came back and restarted your car) and then it goes away, its as if a pod is sticking open for that amount of time and then it closes some flap somewhere and everything is good and I get cold A/C air.

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1) 84 300SD 285K+ Miles (Ver Calif)
2) 84 300SD 175K+ Miles (Ver Federal)

That's normal or at least to be expected. The unpowered position of the monovalve is full open. When you park a hot car, the monovalve opens and hot coolant warms the heater core even if coolant isn't flowing (bad habit, I guess). When you start the car, the monovalve closes so AC cooling can take place but it takes a while to overcome the heat soaked heater core. I imagine that as the monovalve ages it takes longer to close and closed might not be as closed as it was when new.

BTW, I'm not making a distinction between the monovalve assembly and the replaceable monovalve cartridge in this context.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD