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Blower motor only coming out defrost

xactorocker

NAXJA Forum User
Location
Atlanta
Hey, I recently bought a 1992 xj and i was able to get the blower motor running the connector had melted. but now the air only comes out of the defrost vents. I have heard it is a vacuum hose that controls this anyone know what hose it is? thanks
 
All of the vents are activated by vacuum diaphragms. There is a little vacuum manifold on the rear of the HVAC control unit that routes engine vacuum to selected appropriate diaphragms. The defrost vents are normally open and closed by vacuum.

If you have weak vacuum from the engine or if there is a problem with the vacuum routing in the cab, you will only get defrost.

Most common issue is the vacuum reservoir ball behind the bumper is broken or removed.
 
Virtually any vacuum line can cause it.
 
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