Where do you put freon in a 1991 Ford Ranger?

The freon (R-12 or R134a depending on if it's been converted) in a 1991 Ford Ranger goes into the low-pressure side of the air conditioning system. There is a low-pressure service port usually located on the accumulator/dryer or sometimes on a nearby line. This port is typically capped and will have a schrader valve. You'll need the appropriate tools (manifold gauge set) to add refrigerant properly and safely.

Important Safety Notes:

* Do not attempt to add refrigerant without the proper tools and knowledge. Improperly adding refrigerant can damage your AC system and is dangerous.

* R-12 is a harmful ozone-depleting substance and should not be added. Most 1991 Rangers have likely been converted to use R-134a, a more environmentally friendly refrigerant. If it has not been converted, you need a professional to do this conversion safely.

* Always wear safety glasses when working with refrigerants.

* Have a professional diagnose the problem before adding refrigerant. Simply adding freon won't fix a leak or other compressor issues. Adding freon to a system with a leak is wasteful and harmful to the environment.

It's strongly recommended that you take your 1991 Ford Ranger to a qualified automotive technician for AC service. They have the proper equipment and training to diagnose and repair any issues with your AC system, ensuring it's done safely and effectively. Attempting to recharge the system yourself could result in damage to your vehicle's AC components or even injury to yourself.