i have a 1985 190E
the problem with it is the heating will not shut off
it continuously comes out of the defroster and the two vents near the passager and driver. When i try using the air conditioner, the heat still comes out of thoses vent and will not shut off even if the close vent button is push.

any help is appriciated.

Bob

The heat/cooling system operates off of engine vacuum, any vacuum leak the system in will cause it to go into a heating mode.

The two problem areas in the vacuum system for the heat are the vac line that travels under the battery tray. (It gets acid damage and leaks). And also the line that connects to the intake under the air filter housing. Also there is a valve located under the black plasic panel under the hood. Take off the panel and look under the windsheild there will be a valve with a vacuum line connected to it. This is the heat valve and should have vacuum going to it to turn off the heat.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
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