Hey fellow Rangers! I just bought a 2001 Ford Ranger yesterday and the AC does not blow cold.

At the dealership we tried adding more refrigerant using one of the handheld cans and the gauge said that it was adequately charged.

When the AC is on, the AC compressor clutch goes through a cycle of engaging for ~1 second, then disengaging for 5-10 seconds before engaging again. And it just keeps doing that.

Any ideas on what the issue could be? Where should I being troubleshooting? Thanks!

 

Start with the freon pressure switch on one of the freon lines. You can test it before buying a new one by pushing a sewing pin thru the two leads to the switch, shorting out the switch (thats what the switch does if there is enough freon pressure)
I had this problem on a Honda and when I shorted the two wires the AC stayed on. The freon level was fine but the switch had failed! Just dont leave it shorted unless the AC comes on because if the Freon really is low, you will destroy the compressor as it uses the Freon for lubrication.

 

Thanks I'm going to try this! If it does end up being a bad pressure switch, would I need to drain freon before swapping it out? How can I tell if I need to evacuate the system or not?

 

well, if its just a bad switch, you can replace it without flushing the system. Wear gloves and use one hand to remove the old switch and use the other hand to put in the new switch. You just have to be fast and dont have the engine running, and you wont loose much Freon. But wear gloves so you dont freeze your fingers.
Most of the time its not necessary to evacuate the system, There isnt any way it can get dirty unless something fails internally.
BUT, a year ago the AC on my Lexus LS430 died after 20 years of service, I thought in must be the compressor because 20 years is a long time to run an AC Compressor here in the deep south of Texas. I checked the pressure and the pressure switch and all was right so I took i to the dealer expecting a $2,500 bill. They removed the Freon, cleaned it and put it back and, lo and behold, its been working fine ever since. The dealer could not believe it nor could he explain it. Just $250. But check that switch first, its cheap.

 

Okay so I short circuited both the high and low side pressure switches using a paper clip. I confirmed the low side pressure switch is where the problem is because the compressor clutch stayed engaged while that one was short circuited.

I have a new low pressure switch coming tomorrow and will replace it. I’m just nervous the coolant is gonna come out while I’m replacing it

 

Better wear gloves and eye protection. You don’t want that stuff in your eyes. Better yet see if you can get a face shield.
personally I would have it professionally captured, replace the low pressure switch snd then return the Freon. There’s lots of places that can do this. Good luck.

 

Okay I hooked ac pressure gauges and ran my ac. Again, the ac compressor clutch engages for ~1 second then disengages for 5-10 seconds, before starting that cycle again.

I found that the low side and high side pressure sought equilibrium when the compressor clutch was disengaged. When it engaged for the second, the low pressure side decreased slight and the high pressure side increased slight before disengaging and seeking equilibrium again.

Here’s a link to what going on:
Thoughts on what this could be??

 

low freon. The pressure drops because it runs out of freon to pump. Needs to be evacuated and refilled

 

That’s exactly what it was. I made a video for future Ranger posterity.

If you stumble in this post because you’re experiencing what I was, I hope this video will help!

 

As jim said, you have low refrigerant. If you flush the air out of the fill hose and hook up to the LOW pressure port, the 1 second on time will increase as the refrigerant goes in and eventually it will run nearly continuously. It may take 15 minutes or so. Open the valve wide open and set the can upright so only gas goes in. You read the pressure only while the compressor is on. When it gets up to about 35 pounds you are done. You likely have a leak, but with no history it is hard to know if it is bad enough to require repair.