Quintin: Just got back from NC. Compressor doesn't cycle now with max ac on and it cools down to abt 52 at vent with ambient temp above 90 and very high humidity.Like you said, It quit cycling once warmed up good and higher outside temp. how much 134a do you think I need?

 

This is the point where it's hard to say how much you really need. If it's an option, and for best performance, I'd have the system completely recovered, evacuated and recharged by an A/C shop or someone that has a charging station. If you don't want to go that route, I'd say add no more than 12 ounces.

 

Thanks Quintin Thats probably the best thing to do because I don't know how much is in there now. Its cooling nice now so I won't have to take it in during the hot weather when everyone is busy fixing AC units. I can wait till its convenient. Thanks for all your good advice

 

Here is the story/situation....hope you got a couple of minutes...........My dad has a 99 F250 SD with 152,000 miles. He is making a trip from Syracuse, NY to Nashville, TN and has NO a/c. I've tried to everything that I can think of,......new refriderant, fuses, bypassing the switch on the side of the compressor, I've even tried to move the compressor clutch by hand (it moves freely). I'm stuck. Do you have any suggestions, or is it time to go to the pro's.

Jason

 

Me? God? Haaa...I just do what I can.

Now, onto your Pa's F250. The switch on the compressor isn't the one you want to jump. The only connector on the compressor is the two pin connector to the clutch itself. Nearby, on the high pressure line next to the compressor is the high pressure cutout switch. The low pressure cycling switch, mounted on the accumulator, is the one you want to jump with a paper clip or piece of wire. You should have power on one side of the switch with the A/C on, pink wire I believe. Jump that switch and see what happens.

Standin' by...

 

........ Um, sorry for the misunderstanding, that is the one we tried, not the compressor. :o

 

Okay...will update later this morning, I'm sleepy. In the meantime though, make sure you've got power at the low pressure switch connector itself.

 

My neighbor was complaining that his 97 F150 air conditioner was cycling really fast and he thought it was low on freon. Then all of a sudden the compressor quit engaging. Followed the wires back and checked the diodes, relay, etc. but still couldn't find problem. Took it to the dealer and they found what he called a heater switch on the air conditoner system that was malfunctioning and wouldn't let the compressor kick in. He said the way to tell is to turn the heater on and see if the compressor kicks in. If it does, the switch is going bad. Have not had it happen to me yet, but seems like its worth checking out. I don't know exactly where the switch is located on the system, so one may have to call the dealer. Also I believe this is only for the vehicles with the automatic climate control systems.
I am just passing this info along, sorry that I don't have specifics. Maybe someone else can elaborate more.