My ac randomly went out. I assume it just need recharged, but at the same time the slider to send it into cold refuses to slide past room temperature. I'm not entirely sure if theres another symptom or if this is just because the system is uncharged? Any ideas? AC completely vexes me.

 

YEAR of the Ranger would be helpful, always?

1994 and earlier use a slider and cable to control the Blend Door

If you open and fold down the Glove Box all the way you can see the end of the cable and its adjuster, at the top of air plenum
The Blend Door directs air thru the heater core(Hot) or around the heater core(Cold), or anywhere in between

It could be cable has slipped or blend door is stuck, or the slider itself has a problem
Nothing to do with AC system though, but the temp of AC, yes

The AC evaporator(the part that cools the air), is in the fan box in engine bay, all air passes thru the evaporator FIRST, all air
Then it goes into cab and is either diverted around the heater core(cold) or passes thru the heater core(hot)
The evaporator is used to DRY the air even when AC is off, this helps to Defrost windows and keep humidity down in the cab in general, so avoid musty smells in humid areas

 

Its a 1989. I shall investigate behind the glove box. I can't imagine i blocked it somehow but i shall see. I recently changed the radiator and flushed all the lines. don't think i snagged anything but I shall double check.

 

Nothing in the engine bay would effect the temp slider, its just a cable that moves a door, all inside the cab

 

I see the 2 or three cables behind the glove box, using the slider I think i can find what cable it is but there doesn't seem to be anything binding. I can hear a flap behind the dash though, like a door panel is hitting something before the slider reaches the far left. I assume that is my problem and i have to find this door.

 

Its called the Blend Door and very very hard to get to

Your best method will be to cut an opening in the air plenum big enough for your hand to get thru, seen in this video


The colored "wires" on the left are NOT wires they are vacuum hoses for the vents, so don't nick them
Your 1994 uses a cable to control Blend Door, 1995 and up Rangers have an electric blend door, which often broke, just FYI

Once you have the hole cut you can reach in and feel if something is blocking the door
Use Duct tape to seal the hole

 

Don't have vacuum lines in here it seems. I can hear the blend door behind that plastic. just hesitant to cut into it. The arm that moves the door looks to be fine though its clearly working, its just like the cable got shorter somehow.
I seem to have a compound problem now. turned the fans on to keep cool while digging in, and at max speed it feels like its on the first setting. first setting is just a gentle wiff of air. I don't think i'll be able to sneak by without taking this dash apart now.

 

It reads like you have something blocking the air passage, so cut the air plenum as described to get hand, and eyes, inside

Does/did the truck have AC?

 

Yea. It has AC. I swapped the radiator out and I think the old seals on the hoses let the ghosts out when i was moving them around. So it doesn't currently work. Thats when i noticed the hot/cold slider didn't go to full cold side anymore as the ac wasn't getting cold anymore.

 

If truck was ever parked outside you may have a rodent that moved in and setup house in the air plenum, nesting material is blocking air and slider movement

You can pull out the fan in the engine bay to have a look as well, just 3 or 4 screws

 

Hmm. took the fan out. nothing blocking it. moved the dial to all speeds, and the fan sped up as expected. I'm guessing this door to let the air in isn't opening. something is unplugged or that vacuum actuator isn't working.

 

There is no "door to let the air in"

From fan hole feel in towards the center of vehicle, the AC Evaporator is there, its like a radiator, lots of fins, make sure its debris free

Air flows thru the evaporator fins and into the cab air plenum, no door there, and is either routed thru or around the heater core, no way to block the flow there

The vacuum vents, floor, panel or defrost, just route air flow they can not block it, even if all are closed or open the air just flows out in a different direction

Defrost vents are the default setting if there is no vacuum, all vents open sends air to defrost vents

 

Alright maybe just taking the fan out helped it because it does feel stronger now. motor might be getting weak.
There is def a little door that opens directly after the blower, it seems it only opens when "max ac" is selected. Unless i'm missing a few components it just seems to blow air directly into the cab from behind the glovebox.
I did feel debris in the corner. i'll have to dig deeper. was a bunch of small leaves and dirt in the corner of the blower box itself, so its reasonable this radiator would get some also. I'll slice into the blower box tomorrow and see what the door is up to. Is there an adjustment somewhere? Feels like its hitting the bezel on the dash before fully opening on the "hot" side also.
I need to convert the AC lines to the r134 fittings. I took a cap off just to see if it had pressure and it does, just barely.

 

The door straight ahead of the fan is the INTAKE, its where the fan sucks IN air
Directly above is the fresh air intake, under the cowl, between hood and windshield, there is no easy access to it from the outside
The door closes in MAX AC so air is sucked IN from the cab, to recirculate the already cooled air instead if trying to cool hotter air from outside, so Maximum AC cooling

So no air should go OUT that opening directly in front of the fan

Air from the fan goes OUT to the side and thru the evaporator

 

Alright that makes good sense on that door. didn't think about it.

I cut into that plastic cover. there was just the heater core radiator behind it. So i took off the bottom cover. This door looks to be behind it and to the side. I can see it move when i play with the slider, it doesn't seem to close all the way and takes 3 clicks of the slider until it starts to open. Why this would prevent the slider from going full open i don't know seems like i should have the opposite problem.