I have a 2002 3.0 FF and this problem started in October, but I didn’t worry about it too much since it was getting colder. The AC in the truck works, but it takes about 8 minutes for it to finally kick in. I’ve noticed that the issue isn’t because of the engine warming up as no matter how long the engines been running, it still takes about 8 min after turning on the AC. When I hooked up the ac pro thing to it, the gauge said “see instructions”. I know that The ac pro thing still works because I just used it on my sisters suv. The last thing to note is that when the ac is initially turned on, it has a mildew smell so I would assume I need to kill that bacteria and change the filters.

 

I can't help too much, but here's a quick and free test to rule out the relays. Find the A/C relay in the engine bay fuse box and swap it with another relay of the same size/pin count (Find one that isn't gonna keep the truck from running well).

Now drive the truck and see if the problem has gone away. I had an issue years ago where my A/C would take forever to work and even then it wasn't that good, and swapping the relays around fixed the issue. I made sure to replace the defective relay right after the test. I got lucky with that fix, maybe you can too, but no guarantees.

 

Test your TEMP ****
After engine is warmed up AC OFF
Turn fan on and set temp to hot
feel air temp, should be very hot, 160degF hot
Then turn **** to cold and temp should drop quickly

TEMP **** operates the Blend Door inside the cab, its electric, the Blend Door covers the heater core, so with **** on hot all the air from the fan is sent thru the heater core, in cold none of the air from the fan goes thru heater core
And it is of course adjustable for anywhere in between

Blend Door actuator(motor) is a common failing on Fords, not just Rangers
If it was stuck partially open it would take awhile for AC to overcome the heat of heater core

AC system can be over filled
AC systems work by compressing "freon" to a very high pressure(250psi), then releasing it into the low pressure side(40psi), if over filled the low pressure side is not very low
The difference in pressure decides how cold it gets
If system gets low on "freon" it actually works better but..................drops below 32degF and causes system to FREEZE up, so stops working
Generally speaking system should cool to between 38-42 degrees

 

There are no filters on the ranger HVAC. The cowl more or less creates a direct path to the HVAC system. While simple, this does allow a buildup of dust, debris, and even bugs to find their way against the evaporator core of the AC system.

To clean, you'll want to start by taking the blower motor out of the HVAC box in the engine bay. From there, use a mirror, and peek "around the corner" at the evaporator core. The corner where the lines enter the box is incredibly difficult to get at. It is also where 99% of all the debris and dust/refuse collects on the evaporator core. This "stuff" will cause the HVAC system to smell mildew-y and musty.

After you have cleared out all the stuff you can clean out, physically, you can carefully use a hose and do a few quick "blasts" into the core, if your condensation drain is not clogged. If it is, get under the truck, locate it, and unclog it.

After washing some of the large bits out, take the blower motor and reinstall it. After it has been put into place, grab a can of "Kool-it" from Amazon, or the parts store if they have it. Hell, grab 2, it wont hurt


You'll shove that guy "up the wazoo" (drain tube, LOL) on the HVAC evap box, and more or less empty the can into it. It creates an emulsifying foam that smells "minty fresh" and really, REALLY does well to clean off the evap and heater core of accumulated dust and debris. It can also help dislodge any stuck on gunk and refuse that was stuck in the core from the great outdoors. I have personally used this stuff and it works great. I will express that you should allow it to drain for about 30 mins, and then turn the truck on, cycle AC on to help wash out any remnants of the cleaner. Then, use the heat side to dry out the HVAC system beyond the heater core. I did not have the opportunity to get under the truck when I did mine, so I just hosed it down from the blower motor opening. While it did work, I am sure that going in through the drain is the best option, as it allows the foam to "push" the debris back out of the evap core before it breaks it down into a liquid to drain out.