Dashboard Air Duct Does Not Switch Properly
 

Gentlemen. In my 1999 Ranger, I can flip the air outlet switch to cause the air to exit either up, down, or straight out -- except that most of the time the air WILL NOT come straight out the dashboard ducts. I am assuming that there is some kind of diverter valve inside the dash that is intermittently working, but I do not know how to get to it. Do I remove the radio panel? If so, how? Or is there a way to get to it some other way, like from underneath or through the glove box? Does it just need a shot of WD-40 to free it up? :-huh

I'm not sure how you'd get to the diverter, I wish I knew. My '94 Ranger gets hard to switch from hot to cold sometimes,& I'd like to fix that.

I know that a lot of the interior parts will "pop" off if the right screws are removed. Remove screws & a little gentle prying will often do the trick, I know that's how I put in my stereo.

When I have a little time I'll see if I can find any info on this. For now, I'm subscribed to the thread.

You Have to Know the Tricks
 

Yes, things come apart when you know how to do it. Unfortunately, lots of things are put together with plastic "snaps" that often break when they get old and brittle. I generally spray WD-40 into areas that might have the "snaps" so that hopefully things will come apart without breakage. I preferred the "old days" when everything was screwed together with visible screws. If you know how the radio is removed, please tell me. That would be a start. :)

Kinda sounds like the blend door belongs on your suspect list. The control arm plastic piece breaking,is a common problem part. Here is what it looks like & a method one FTE member used to repair his. 1998 Ford Ranger 4x4 - Blend Door Fix


If you'll go to this forums index page & type in blend door, or blend door fix, you'll find plenty of posts on the subject. Let us know what you find & how it goes.


Or maybe a vacuum leak to the heater/ac control panel plumbing.

I Don't Think I Have a Blend Door Problem
 

Thanks for the suggestion, but I don't think it is a blend door problem. The transition from hot to cold and back again seems to work fine. The problem is that most of the time I can not get the air to come straight out the dashboard vents, even though the output setting shows that the air should be coming straight out. Even when the air is coming straight out, as directed, it will change, on its own, to stop coming straight out without any input to the switches. I am able to control the temperature of the cab -- I just can't control where the air will come out. I think I have to take the dash apart to see how the air diverter system works, but it is not obvious how to take the dash apart. Any ideas? :-huh

Be sure to check the vacuum lines to the control panel, as its configured in case of a failure, to divert air flow through the windshield defroster ducts.

I Think You are On to Something
 

It does seem like the air diverter system on my truck is defaulting to defrost mode. I don't understand why it would do that, however, when it seems to work fine some of the time. Is it possible that there is a spring which causes the default mode, and to make it different you have to "hold" vacuum on the diverter? Maybe there is a leak that prevents the system from holding vacuum? Your thoughts please. :-huh

Yup a system vacuum leak is what I've been suggesting. Perhaps begin by looking under hood where things are subject to plenty of heat, for dryrotted vacuum lines or soft, mushy, loose vacuum line connections that run to the firewall & feed through to the heater/ac dash control panel & to the under dash control door actuators & let us knows what you find.