My A/C is cycling every 4-5 seconds. I have read where this points to low freon, so I had a shop replace a leaking schrader valve and evacuate and recharge the system. No difference. What else would cause this quick cycling. I have a 2000 3.0 Ranger.

 

Is it only at idle? In my 96 2.3 this was caused by an idle air control valve malfunction (I've seen it in a 97 as well). This seems to be a common problem based on searches here. My cycling was closer to 3 seconds. I also occasionally got high idle due to sticking at the high side when coming to a stop. It's a two-screw DIY swap if this part it your issue.

 

Hello, welcome to FTE!

We have a whole forum just for AC questions where the HVAC experts hang out!
https://www.ford-trucks.com/forums/forum61/

 

How is the output in the cabin? I mean, are you getting plenty of cold air out of the vents. Normal procedures at most shops after servicing the AC system is to measure the system pressure and measure the temperature of the cooling air. Check your receipt to see if the shop recorded this data.

I have received good input from the members on a related topic in this thread which you may want to follow.

 

The cycling issue will happen at high speeds (75-80) or at idle. The cabin air is very cold, even before I had the work done. The work order shows the pressure and temp. good. Thanks for all the help.

 

Maybe an overly sensitive, or out of spec. high, or low side cutout pressure switch.

So if a proper system high & low side presure check shows things to be normal, I'd maybe suspect one of the pressure switches & test to see which one is opening prematurely.

From your description of the A/C cabin air temp being plenty cold, I'd probably lean more toward an acting out high side pressure cutout switch, so you might start your testing there, while you monitor the high side pressure, to see when it opens.

Let us know what you find.

 

I have a 2000 Mazda B3000 (Identical to Ford Ranger 3.0).. mine does pretty much the same thing.. even the other day when it was almost 90degrees out. The air coming out the vents is very cold.. just keep in mind that's what's important. From what I've noticed on mine, it's a very good working A/C system.

When the low side pressure drops below a certain point, it kicks off the compressor. This is most likely caused by one of three things. 1> Low Freon level (Low level = low pressures). In this case you'd have poor performance. 2> Restriction in system (possible plugged oriface tube)... which again would equate to poor performance. and 3> Evaporator freeze-up.. basically the system is working almost "too good" and it kicks the compressor off just short of the evaporator becoming a block of ice (which is a good thing) because if it froze up you'd have almost no airflow coming out of the vents.

As long as you're happy with the temperature and volume of the air coming out of the vents, I wouldn't worry so much about what the compressor is doing. The low and high side pressure switches will prevent almost any damage from occuring to the compressor.