Ok, here goes: 97 Ranger, 110K mi, XLT Extended cab Splash;
When I turn the air to the blower, it is all hot air. I can put it all the way to cold, and it blows very hot air. If I turn it on regular A\C, it is hot. It only blows cold air when I turn it to Max A\C. Any suggestions?

 

Sounds like your blend air door is stuck or sticking. If you get cold car in Max a/c, your compressor and a/c should be good. All Max a/c really does is use inside air instead of outside air to blow across the a/c core.

 

Max AC also shuts off coolant to the heater core. That is why it is cold in Max AC. My guess is you have the ubiquitous Ranger/Explorer Blend Door problem. Now, it could be something else, like a blown actuator motor on the blend door, but I give it an 90% chance on the blend door. Check the technical info sticky in the forum for a link to the blend door diagnoses and fixes.

-Jim

 

I worked on my neighbor's 97 with the same problem. His was always cool never hot. I took out the glove box removed the blend door servo motor and saw it turned when you twist the hot/cool ****. I then looked into the hole for the blend door motor and found the square plastic peg on the door that fit into the motor had broken off. Actually I couldn't see into the hole I had feel with my pinkie finger. I told him I needed to drop the whole hvac box and he decided to call the dealer. The dealer told him $1500 to replace the box, heater core and A/C Evap. He asked me to do a cheap fix and I told him I could set him up with "manual heater controls". I used a hole saw and drilled a 2" hole in the bottom of the box directly under where the blend door sweeps. To switch from heat to cool he had to stop, lean over to the passenger side and put his finger up into the hole and flip the door to one side or the other. He was pleased to get a cheap fix and I made an easy $50 by drilling a hole in the right place.

 

Nick,

Unfortunately, we've lost the tech info sticky for the moment, I hope that there is a replacement soon.

Your "manual" fix is an option but I would recommend reading:

Blend Door Fix

If that doesn't work, options are a solution like yours, or replacing the plenum as you mentioned. The bill that the dealer quoted is not that off mark (though it seems a little high). The job is mostly labor since you need to pull the dash out to get the plenum out, though discharging the AC system is not necessary (but probably listed in their repair book). A used plenum can be found for $100 or possibly less. I detailed how I did it in this thread:

Heater Plenum Replacement


-Jim

 

My Ranger has had this problem for years. Of course the mechanics never knew what to do or they wanted me to mortgage my house to fix it. It really needed to be fixed tho because you cant get fresh air from the vent when its broken like this. I was finding that the Max AC was pulling in exhaust fumes from under the hood with the fan cranking and the vent closed off. For some reason my ranger has always smelled bad but no one can find a leak. Long story short, I read all the various fixes and finally decided to go at it with my hole saw like above. It worked like a charm. I just use a hobby clamp to keep the door on the correct side and the hole I drilled just becomes an extra blow hole. Here in san diego I rarely ever need heat, so I wont have to move it much. I just want fresh air. Im no longer feeling like Im going to lose a lung after a day of driving around. Thanks for the idea!