If my a/c is now blowing warm air, could adding 134A refrigerant oil fix it?

Approximately 2.75 pounds for a gas or diesel and additionally, 7oz of oil for gas, 10oz of oil for diesel. Some refrigerants have the mix/ratio of oil already in it.
If you convert or use 134a you should use only 80%
or 2.6 pounds. Remember overfilling is not always better. Too much and you blow warm air.
Amazon com auto refrigerant Automotive

Check out this awesome chart for Ford Vehicles...
http://www.m-m-s.com/ACKits_public/Files/RefrigerantCapacities.pdf

purge system might b over charged &check &make sure compressor is running

The Problem is the refrigerant. R-134A doesn't last as well as the old R-12. Best bet is to "evacuate" the system, and recharge with new refrigerant. Your system should take 1 can of R-134A Oil with Conditioner, and about 1.2 cans of R-134A refrigerant. The system is easy to work on, and rather in-expensive if you do it yourself. You should have a certified auto repair center do the "system evacuation". I hope this helps you, and I wish you luck on the repair.

Hi,
A couple of things will cause this problem. The first is making sure the compressor has voltage (blown fuse). The most common is it is low on refrigerant. Freon 134a. Good Luck.

probably a leak.

what are your high and low side pressures?

In most cases, the problem is the system is low on refrigerant. The AC compressor requires a minimum of 20psi of refrigerant to turn on. There are refill kits available at the auto parts stores. If doing this yourself, select a kit that includes compressor oil, and a refill hose.

RECHARGING AC SYSTEM

1. Turn the truck on and turn AC on HIGH
2. Locate the low side AC line (will have a valve and cap similar to the cap on a tire)
3. Insert the oil or R-134A can to the hose (Do not turn the screw to puncture the can yet)
4. Insert the other end of the refill hose to the low side valve
5. Puncture the R-134A can with the screw on the refill hose
6. You should feel the system suction the refrigerant out of the can
7. Check for frost on the AC lines and the air blowing inside the truck
8. If frost develops and the air is cold, you've successfully recharged the system and disconnect the refill hose. DO NOT ADD MORE REFRIGERANT...overcharging the system will damage your compressor and will be less effective

Hopefully this answers your question and you're able to get your AC working again. Best of luck.
Greg

check the service ports if they are screw type it is r 12 if they are quick connect type it is 134a yes you canconvert it i do it all the time
go to autozone or oreillys and get a retro kit (a little box of fittings) about $7 3 cans 134a and ester oil vacuum system down with pump for 30 min add 2 oz oil and 2 1/2 cans 134a.

Most likely cause is a leak in the AC system. Adding refrigerant alone won't cure your problem. Get a can of R-134A with leak detector in it. It has a UV dye that will glow wherever the system is leaking. Best of luck.
Greg

The system could be low on oil. The compressor will shut itself down if it detects a lack of oil or refrigerant. Try adding compressor oil (comes in a can similar to the R-134A) to see if the compressor will stay engaged long enough to accept a charge. It's also possible that the system has so much air in it that it needs to be evacuated before refrigerant can be added. I'd try to add the oil and see if you have better sucess adding refrigerant REMINDER: Have AC on HIGH when adding refrigerant with car running

Hope this helps with your AC problem. Please post back with any other questions. Best of luck.
Greg

There are special cans of R-134A with dye in them for detecting leaks. Most leaks occur around the fittings near the compressor. Recharge the system with the leak detector can or R-134A. There are also cans of R-134A with an additive to stop leaks. I would use these products to either detect your leak or to stop it. Best of luck.
Greg