2003 Mazda B3000.

This was never an issue until recently. When the AC was on cold, you’d hear the AC clutch cycle, and with the heat on, I’d never hear the AC clutch cycle as it shouldn’t. As of a few days ago, with the heat on as usual, the AC clutch is just starting to cycle rapidly as I drive.

and by rapidly, I mean that the AC clutch is clicking on and off every 8-10 seconds give or take. Followed by the rapid cycling is the idle going up by 700 or so RPM.

I thought the AC had nothing to do with heat? Why is this just happening now? Did anyone else have this issue in their ranger?

 

AC is used year round, nothing to do with TEMP setting

AC is used to cool but ALSO used to DRY the air being blown into the cab by the fan

The heater core can over power any cooling that an AC system can provide, so it can never take away max Heat in the cab, its just used to DRY the air

Ever notice the water that drips out behind passenger side tire on ANY vehicle with AC, that's from the Evaporator, the part of AC system that cools the air, its inside the "heater box" in engine bay
All air from the blower/fan passes thru the Evaporator before going into the cabs vent system
The cooler surface on Evaporator causes water vapor in the air to condense on its surfaces, like water condenses on the outside of a COLD glass of beer on a warm day, lol
So its DRYING the air

In a 2003 Ranger the AC should be active in all settings EXCEPT FOR , off and vent
This is done to DRY the air for Defrost and in other settings so cab doesn't get musty smell in colder wetter months, you bring alot of water into the cab when its raining or snowing, and even from just breathing year round, lol

But from your description your AC system may be low on "freon" causing it to cycle too much, so could have a leak, or blockage
AC systems have a high and low pressure switch
If "freon" gets too low the AC compressor can burn out so low pressure switch turns compressor off until pressure gets higher again as it circulates from high pressure side
OR
If there is a blockage in high pressure side, the high pressure switch turns off compressor so it doesn't BLOW OFF connections, then as pressure drops compressor comes back on
So with either scenario you get a faster cycling on and off

If your AC was working better than usual last summer then its most likely low on "freon", low "freon" causes over cooling and can even cause AC lines in engine bay to get frozen water on the outside, thats a bad sign not a good sign, lol




AC only has ON/OFF there is no TEMP control
TEMP control is only about heater core
If TEMP is set at COLD then no air passes thru the heater core
On HOT all air goes thru the heater core
This is done by the Blend Door inside the cab

So the TEMP control moves the Blend Door which then diverts some or all the the air thru the heater core, users choice
The heater core is at 180+degF, coolant temp
AC Evaporator runs at 40degF
So if user wants 75-80degF cab temp you can easily see the Heater has the upper hand, lol, over any cooling that the AC system can provide, 100+ degF better

MAX AC just closes the outside air vent, so fan pulls already cooled air from inside the cab into the fan, which is then recooled by Evaporator
So instead of pulling 90+degF air from outside cab, to cool it, it pulls in the cooler cab air so it can cool it more
So faster and better cooler temp

Also good to use MAX AC on dusty roads or anytime there are outside "particles" as MAX AC closes the outside Vent, and you can still adjust TEMP to warm or cold, as said nothing to do with AC settings, heater WINS out, lol

 

Just wanted to thank you for this reply as it does help me understand the AC system a little better. As far as the Freon goes, mechanic said I do not have a leak and it’s right where it should be. My Compressor is probably on its way out from what I understand. I’m going to try and replace the AC switch first. Maybe that’ll help before I have to tackle such a big job.

Thanks Again!

 

Yes, the pressure switches are "hot swappable" meaning you don't have to drain and refill the AC system to change them

Good first step

 

MAX A/C on some models (if so equipped) will activate the heater core bypass valve, and redirect the coolant to not circulate through the heater core. I ended up deleting mine as the OEM burst, and the aftermarket unit broke on me a year later.

 

Yes, that is true on the 2003 Ranger, actually 1995 and up Rangers

But on ALL vehicles, MAX AC closes fresh air vent and recirculates cab/cabin air, Ford, Chevy, Jeep, ect...............one thing they all have in common, not a truck thing either, cars as well
The one thing I remember growing up on dusty roads, "Leave it on MAX AC all the time", lol

 

Lol dusty roads.

I just learned to breathe through my nose, lived on dirt for 20 years. With a home on the east side of the road that went N/S, dust was a pretty familiar friend of mine

Got pulled over once in a town not 20 mins away, as a very fresh "adult"
Officer is hassling me about not being able to read my license plate, as an adult knowing it was just a fishing expedition.

I'm trying to resist the urge to get some sort of charge by asking him "you are aware that dirt exists outside this paved city, right?"