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Repairing air vents in a Prism

A few months back then vent controls in our car broke. Basically, its now stuck on the defroster and the knob to switch it to vent or floor or whatever doesn’t work.

I’m guessing this isn’t too hard to fix, but how do I take things apart to get at the problem?

Also, where should I look to find a replacement driver’s side mirror? Not the whole mount, just the mirror itself. The dealer or is there a less expensive option?

You may be able to find a repair manual at the library or the auto parts store.  I should say that job can be one of the most difficult jobs you can do because of the limited access.  It might be easier if you have a teenage son or daughter that happens to be small and have long fingers.

Does anyone have any more specific info? I plan on getting the manual at the library, but those fancy diagrams are a lot less helpful then someone just telling me to pop panel x off at corner y using such and such tool…

In most cars the controls you refer to are vacuum controlled. When you have no vacuum to the system, the air goes to the defroster as a safety measure. The vacuum comes from the intake tract of the engine. There is a check valve and a reservoir between the AC controls and the engine. This stuff is usually under the hood.

You have a vacuum leak somewhere, a big one. With a small leak, the AC controls will work unless you have low intake vacuum (when your foot is on the accel pedal hard).

I am not sure what you mean about the mirror. Try an auto glass shop or a salvage yard.

A service manual, such as Haynes (or a factory manual if you can afford it) will show you, step by step, how to remove and replace the ventilation controls, or anything else you want to repair. These manuals are invaluable if you’re attempting do-it-yourself car repair.

If only the glass is broken in your side mirror, you should be able to get a new mirror for not much money at your local auto glass store. Check the yellow pages in your local phone directory.

Thanks for the input folks.

BeadsandBeads, my problem is that the knob won’t turn, it get stuck on one or two positions, turning difficultly even between those two. Would you still say this is a vacuum leak, to me it seems like the controls themselves are jimmied up, but really I have no idea.

I actually have a auto glass tech coming out tomorrow to replace a cracked windshield so I’ll call them in the AM and ask about it.

I have the Hayes manual on reserve at the library… unfortunately it may not come in until after my big road trip next weekend.

It sounds like the control is broken. I could not make that out from your original post. Usually these “defrost default” symptoms are a vacuum leak. Usually the plastic trim on the dash can be gingerly pried off.