93 Explorer, air vents leak when closed

[ITBEBOB]

I have a 93 Eddie Baurer Explorer that I bought new. I've taken excellent care of it and have over 249,000 on the engine, which runs like a top.

1. For several years I've had a rattle under the dash board and found that if I move my heater/AC selector lever to the right the rattling stops. What could it be and how would I fix it?

2. When the vehicle was new I could select MAX on my AC and no smells or dust would enter the car. Now when I select off or MAX and are behind a diesel truck or bus my car fills with the fumes. How do I fix this problem?

3. Just recently I noticed that even when the selector lever for the heater/AC is moved to the off position air still comes out of the vents. The fan is not on. Is there a door that isn't closing all the way? Could it be a cable that is streached or I need a new vent door seal on the vent box?

I would really appreciate some advice on these issues.
Thanks,
ITBEBOB

 

[Roadrunner777]

Wish I could find my wiring manual to confirm, but there is a door that operates to select recirculation versus fresh air. The door is vacuum operated based on the function selected at the dash. So, a vacuum tube runs from the intake vacuum tree to the panel, to a vacuum dashpot, to the door.

Now, I had a somewhat similar problem last year, and I traced it down to an abrasion in a little black plastic vacuum tube in the engine bay. Hard to describe, find the blower motor and my plastic tube had a hole within a foot of it. It was hard to find... a pinhole would do it. I got lucky, it was a clear abrasion, and easy to fix.

All of this is predicated on the idea that a vacuum leak causes the door to go to fresh air, which I had hoped to confirm with my lost schematics. Perhaps someone else can confirm one way or the other.

My advice: Look at the black plastic tubing in the passenger rear of the engine bay. Look carefully, inch by inch. If you are lucky, this is a 10 cent fix.

 

[Jason94sport]

There's a vacuum tube at the back of the climate controls. That runs to a vacuum accurate plunger type thing that is attached to the rec door. All that is under the glove box & passenger kick panel. Take the glove box door off & you will see it.
Mine was broken & would not shut the door. So being in FL I don't need heat & do need AC, I tied the door closed so I have max air all the time.

 

[ITBEBOB]

93 Explorer heather/vent control lever issues

Thanks guys, I'll check out both locations. Never knew how to get a look at the door that opens & closes to let in fresh air.

ITBEBOB