hey all, last week i turned my air con on and it took a while but it finally started blowing out the normal vents. but for a while it only blew through the defroster vents. and it was cool so the compressor was working. today, i drove around for an hour and it only blew through the defroster vents ONLY!
is this a fuse or relay issue? thx yall--jw

i have a 98 explorer XLT.

 

Vacuum leak. Look to see if the vacuum line fell off the water control valve, then look for broken vacuum lines, or disconnected lines under the dash.. Also the vacuum tank may be leaking, which I believe you will find on the passenger side inner fender near the radiator.

 

thx homer will check tomorrow. i forgot to mention, it's not really cold blowing thru the defroster vents. to the point of rolling the windows down.

 

no obvious vaccum hoses unplugged--yet! are some hidden? sorry--no manual here....

 

bump----sorry still no answer

 

Look to see if the vacuum line fell off the water control valve

hey homer, where is the water control valve?

 

The water control valve shuts off the supply of water to the heater core when the air conditioning is set on max a/c. If it's not working the a/c won't get very cold in the max a/c position. The water control valve is located on the heater supply hose and on my 98 SOHC is located near the front of the engine on the passenger side. Check and see if the vacuum hose to the valve has fallen off. It sounds like you might have a broken blend door problem too.

 

thanks gearz, nope---no hoses disconnected. what exactly is the "blend door"? i'm still having the problem. i don't wanna take off the inside controls cover if it's not gonna help...! anyway, still stuck..

 

It sounds like it could be a blend door issue but the simplest to check would be your refrigerant level. Have you ever recharged your system with R-134?Over time it will leak out and need to be recharged. Symptoms would be a increasing loss in the efficiency of the system. You can buy a can of R-134 at any parts house for 10 bucks or less (get one with an attached pressure gauge) and follow the instructions to add it to your low pressure port at the accumulator. It may be all that is wrong with your system. The blend door fix is tougher, mine hasn't broken so I haven't had to deal with it but basically it is a valve which is controlled by your temperature **** on the dash which regulates the temp. of the air which comes out the dash. Read this thread throroughly and see if it describes the symptoms you are experiencing. https://www.ford-trucks.com/forums/s...ad.php?t=24962

 

thanks gearz---killer info. a big DOH for me for not seeing the thread at the top of the forum.......

 

Hello All,

I had this exact problem. Temp control worked, but air (hot, cold, ac, no ac, didn't matter) only came out of the defroster and foot wells. This thread led me in the right direction. It was a vacuum leak.

Here's a little more detail that might help troubleshoot. This is for my '97 Explorer XLT, you're locations may be different, but should be basically the same. This may be a little elementary for some, but until I started researching and looking under the hood, I had no idea where to start.

The vacumm starts at the engine (drivers side, valve cover). It splits and part goes to the emision system (front, drivers side) and part goes around the back of the valve cover. On the right side of the valve cover, it splits again and part goes to, not sure what it is (this component has an electrical connection and a braided line coming in and is near the front of the engine, passenger side), but it doesn't matter, it is the other branch that we care about. The other branch goes to the vacuum resevoir tank (about the size of a black softball) for the ac.

This is where I started. It's not that hard to get to. Crawl under the front corner just below the air filter and remove two screws (9 mm) that hold on the front of the plastic wheel well. Two more (11 or 12mm?) hold on the tank. I didn't need to remove it though as I could pull the wheel well down far enough to get to it. One line goes in and one line goes out and up to the firewall under the heater core. Anyway, I disconnected the line coming from the engine and, with the engine running, I checked for vacuum. It was good and strong. I could feel it with my finger, but put a gage on it anyway and it read normal. Reconnected that and was following the line coming out and going to the firewall to find a good place to disconnect and check it, when, Eureka!, the line was broken in half. It was broken halfway to the firewall, underneath a bunch of stuff where I couldn't see it. So, my problem was before it got to the firewall.

A few additional comments for greenhorns like me if you have checked this far and haven't found your leak yet:
That line (going to the firewall from the resevoir tank) goes into the firewall via a connector that comes in right under the glovebox in the corner (easy to see). It comes in and goes through the control system and back out through the firewall at the same connector (there are two lines at the firewall connector, one coming in and one going out).
I would start either at the connector at the firewall (black line, I think) or at the resevoir tank as they are much easier to get to than the lines up near the controls. You might as well make sure that you have a vacuum at the firewall before taking the dash apart.

Good luck! I know it's going to be nice going to work tomorrow without my windshield frosting up from blowing my AC on it

 

alright, thats a good check and find there. i still haven't got out there and done that.....but will check that first. just find the line starting on top, follow it down to the wheel well? then look for the line going into the firewall.....