How to Troubleshoot a Jeep Wrangler's AC

The AC in a Jeep Wrangler cools the cabin on a hot day. The Jeep's AC system uses compressed refrigerant to cool the cabin. An accessory belt turns a pulley that is connected to a compressor to deliver the refrigerant to the cabin. When this system malfunctions, there are normally only two possible problems--the system is out of refrigerant, or the belt is slipping on the pulley. Before you replace anything, troubleshoot the problem.

1. Open the hood of the Jeep and inspect the accessory belt

Open the hood of the Jeep and inspect the accessory belt. The accessory belt for the Jeep Wrangler is in the front of the engine. The Wrangler uses a rather large compressor on the driver's side of the engine bay on the bottom of the engine. The accessory belt should be wrapped around a pulley off to the side of the compressor. If the belt looks damaged or worn in any way, it may be slipping on the pulley and unable to power the compressor. The belt will need to be replaced.

2. Start the engine and turn the AC controls to the coldest setting

Start the engine and turn the AC controls to the coldest setting.

3. Turn the fan speed to the highest setting

Turn the fan speed to the highest setting.

4. Check the air vents for cold air

Check the air vents for cold air. If there is no cold air being pushed into the cabin, then there is no refrigerant in the system. You will need to have the system recharged by a professional mechanic. If you turn on the AC system and you hear a faint hissing sound coming from the compressor, then there is a leak in the compressor which will need to be replaced.

Warning

If your Jeep Wrangler is older than 1992, you will need to have the AC system serviced by a professional mechanic because the type of refrigerant used in these older Jeeps is no longer commercially available to the general public.

Video: Troubleshooting Jeep Wrangler Air conditioning Blower and Repair

Helpful comments on this video:

• I just got my 2000 Jeep Wrangler back on the road and your video was excellent, I seem to be having the same issue with my Blower... you are a great teacher and excellent Auto Technician. Your video was easy to follow your instructions and explanations were very helpful...
• You are the man! I have to admit that I cheated a little. I did check the glove box fuse and the under hood fuse first, but then I went straight to what seem to be a design issue with the common ground causing the plastic connector to melt. I knew as soon as the connector was difficult to remove, that you had me on the right track. Mine wasn't near as bad as your customer's and I was abble to scrape away some melted plastic and clean the connector to get the system back working. Using your instructions, probably 30-45 minutes start to finish. You save me a bunch of money. Thanks. New subscriber.