Rear A/C

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Aug 5, 2003 | 02:40 PM

Jakea

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Joined: Jun 2003

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Rear A/C

Hopefully this is my last question for awhile! We have never been able to get the rear vents on the roof to work. When you switch the rear a/c on from the front heat comes out of the floor vents. How do we get the rear air to work properly? The roof vents to blow?

Thanks! 1991 4.0L

Aug 5, 2003 | 08:25 PM

HomerWinzlow

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Joined: Jul 2003

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From: Lawton, Oklahoma

Rear A/C

You have a vacuum leak likely. A broken vacuum line is highly possible. I cant recall the exact switch setup on yours, but it may have a vacuum switch integrated into the rear ac temp control like the Windstar. Another possibility is the door actuator at the rear plenum or the door itself is broken.

Aug 6, 2003 | 09:56 AM

Jakea

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Rear A/C

Where do I find the Vacuum lines, to see if they are broken or are leaking? Also where do I find the door to see if it is broken? I looked in the quarter panel behind the drivers seat and everything seems to be hooked together.

Aug 6, 2003 | 10:23 AM

aerocolorado

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Joined: Apr 2001

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Rear A/C

The vacuum motor that runs the air diversion door is on the left side on the backside of the plenum box. You will have to reach back there, blindly, with your hand to locate the motor. There is a linkage from the motor to the door lever. Feel for the lever and have a helper switch the A/C on/off (making sure the rear control is set to operate). You should feel the vacuum motor move the lever if it is working. If no movement, then either there is no vacuum, the motor unit is bad or the diversion door is stuck/damaged. There are vacuum lines directly under the van, below the rear unit. One operates the heater valve - the round affair with heater hoses going to it, while the other line runs up into the rear unit for the vacuum motor.

If you wind up taking the plenum case apart, be sure to get the diversion door hinges back in place during replacement. It is really easy to dislocate the rear hinge when putting the case back together. (This may be your problem if someone else opened the case previously.)

Good luck!