If your vehicle’s AC has has lost its ability to keep you cool, it may simply need a recharge of refrigerant. With a few items from any auto parts store, you should be able to do it yourself.
You will need gloves, eye protection, AC recharge service hose with a pressure gauge, and a can of refrigerant. And maybe a paperclip.
DIY Vehicle AC Recharge
- Connect the recharge service hose with pressure gauge and valve to the can of refrigerant.
- Twist valve counter clockwise until puncture tip is retracted.
- Screw onto the can of refrigerant.
- Twist valve clockwise until it punctures the can’s top.
- Attach nozzle to the low pressure service fitting on the A/C system. It should only match one fitting.
- Turn on the vehicle and set the AC to MAX inside cooling. You should see and hear the compressor engage.
- If the compressor does not engage, you may have too little refrigerant in the system which suggests a leak.
- If after adding refrigerant, the compressor still does not engage, you may have a bad compressor or relay.
- You can bypass the relay with a jumper wire to test the compressor.
- While watching the pressure gauge, slowly twist the valve and allow the refrigerant to enter the system. This make take up to 10 or 15 minutes.
- Feel the air at the vents. It should be getting cold.
- Once you have reached the proper pressure level for the ambient temperature or all the refrigerant has left the can, twist the valve counter clockwise to close it.
- Remove the recharge service hose from the low pressure service fitting. If you used a jumper in step 4, remove it, too.
Get a Pro
Not every vehicle AC problem can be tackled by an amateur. Some problems will need training, experience, fancy tools, and sometimes parts.
- If your car is earlier than approximately 1993, the air conditioning will operate on the now obsolete R12.
- If your system is completely discharged, it may be contaminated with moisture. A pro will fix the leak and remove the moisture with a vacuum pump — a process that takes about an hour.
- If your AC turns warm weeks or months after charging, a pro will track down the leak and replace the part and seals.
- If a part needs to be replaced. Apart from fuses and relays, leave the big items to a professional who will have the proper tools.