I just picked up a 95 B2300 that has an issue with the heater-a/c control. The selector **** doesn't change where the air blows out, it just blows out the defroster.
Where should I look first in tracing this issue down? I'm assuming the controler is vacuum operated.
I haven't found any vacuum hoses under the hood that are disconnected or broke, but haven't had the chance to look under the dash. Since it has had an aftermarket stereo installed, there's not much telling what I might find inside the dash.
Is this controller prone to failure, and is there any simple fixes that I'm not aware of? Such as orings for vacuum or a cable clamp if it's cable operated.

It doesn't have any kind of fancy automatic climate control, just the manual heat/ac system.
Thanks.

 

When there is a large vacuum leak in the HVAC system, the airflow defaults to the DEFROST setting.

Lots of relevant info can be found here: https://www.ford-trucks.com/forums/7...s-on-feet.html

 

Looks like I was already headed the right direction on this.
Thanks for the links.

 

Well, further review shows that I do not have any vacuum getting to the system.
Under the hood, coming out under the heater box is 2 vacuum lines that aren't hooked up to anything. Both were just stuck thru holes in the fender. One is black, and seems to be the line to supply the HVAC system, and the other is gray. Taking a wild guess, I'm assuming the gray is supposed to hook to the heater control valve.
I know the black *should* hook to a vac canister, but I don't seem to be able to locate that critter. Could be hidden inside the fender, or just gone.
The thing that baffles me, is where does the vac canister get it's supply from? I've hunted, and cannot find any capped ports nor plugged lines.
Also, the EGR vacuum system has 2 red lines that come off the manifold, by the booster port. One goes to the EVR (I think that was the letters on the chart), and returns to the EGR valve. The other is broke just past the EVR. Where is it supposed to go? It has vacuum, but not a strong signal (design, or leak?). The vacuum diagram under the hood shows it going to something, but I don't recall the letters used to identify the component, nor could I guess what they were supposed to mean.
Will bypassing the EGR vacuum system throw a CEL or trouble code? I'm tempted to do that, just to finish diagnosing the HVAC issue.

I've tried reading the "Ranger tech" links at the top, but most are dead.......

 

It looks like on the '95, the vacuum reservoir is supposed to mounted just below the the A/C accumulator.

 

Well, perhaps that's where that broken red vacuum line was supposed to go. It sure points in the right direction.
Guess that's another item to add on to the boneyard list. I expected to find a few issues, since I picked it up for $700.

 

Further investigation revealed that not only was the red line that is supposed to supply vacuum to the system broken right by the EGR controller, but the black and gray lines that go thru the firewall were disconnected inside. The firewall connector was there, but nothing was hooked to it. About 4" away, I found the black and gray plastic lines melted together.
About 6" of rubber hose, and 3 vacuum splices, and the system works as it's supposed to.

Also pulled the dash apart to replace the dash light bulbs. 4 of the 5 were blacked. The only one that still worked was between the speedo and oil pressure guage. It's kinda hard to judge your speed at night going thru a speed-trap town, when the lowest readable number on the speedo is 70, and the limit is 45..... Fortunately, the lights behind the HVAC system were functional.
When pulling the dash apart, I found a small flashlight with dead batteries. I guess that was the previous owners answer to the dashlight issue........

Gotta love it. Buy a truck from an impound yard for $700, and find a bunch of small, inexpensive items are all that's wrong with it. Of course, the day I got it tagged, a guy stopped by the impound yard and told me that his uncle bought it new then 3 years later, gave it his grandfather. The grandfather had only sold it to the last guy 2 months before it was impounded, and he hadn't bothered changing the title over, making recovery impossible.

Now, if there was just a cheap way to make this dern thing run as strong as my nissan and get better MPG. Even with nearly 100K more miles (and just shy of 1/4 million), the Nissan will run circles around this one, and get 4-6 MPG better.
3.45 rear axle just kills any chance of the 2.3L having any power or MPG.