I just purchased a 1991 Cherokee. It doesn't seem to be putting out the amount of heat/defrost.... that it should. How can I clean out the outside air inlet? Where is it? I checked at Advance Auto, and they don't even show a cabin air filter for this vehicle.

Any help would be much appreciated.

Dan

 

It might be more likely you have a problem with a vacuum line or valve or diaphragm that controls the vent's...

That vacuum ends up coming from the vacuum ball behind the right front bumper. They fall off and crack....Yours is similar to what is diagrammed in my signature I think.

If you remove the wipers and cowling, then look back toward the passenger side you can see the intake. It's not likely it's clogged if your cowling has been on.

 

afaik there is no cabin air filter.

 

Poke your noggin up under the passenger side dash, just to the right, and below, of where I'm pointing in the photo. With the engine running, move the selector **** and watch what happens when the big flap opens up. The blower motor squirrel cage/fan can be seen clearly. Is it packed with a rodent nest? If so, remove it via the engine bay and clean it out.

 

Right, not unless the mice added one!

 

I don't know how related this is or not, but I pulled my stereo this weekend and discovered that my HVAC system is completely seprated top to bottom. There are two sperated 'halves' where the top half which I assume does the defrost and possibly the upper vents joins the lower half which likely handles all the valves, heating and ac. These two are seperated horizontally with a big fat chunk of foam which was probably intended to seal the upper and lower halves during assembly. The lower half has dropped down and moved rearward (or maybe the upper half move forward and up, not sure where the culprit lies). Either way there is no way the two are sealed together at the moment.

I though mine was an isolated case, but I saw at least one other one at the junkyard this weekend that was the same way. I have to assume that with that big of a hole between the top and bottom halves of the HVAC system, that might explain the problem. It hasn't been noticeable on mine, but I don't drive it everyday. But it may be worth checking into for the price of removing your bezel and popping your stereo out of the dash.