First Post! Excited to be here

Recently purchased a 93 F-150. Its an XLT 5.0 4x4. In the first week I have had to replace the wiper motor and battery. I also did an oil change and a full detail. The seller promised everything worked and to my stupidity I took his word, I know wrong thing to do but the other day I went to turn on the AC and nothing but outside temp air. I checked the low pressure and sure enough it was at 10PSI. So I bought one of those kits to fill it myself, so I did its now at 170PSI but still no cold air. I looked and sure enough the AC compressor is not spinning, I tried to tap it, in case it was just locked up a bit, but still no go. I checked the fuse and it was good. Anyone please help, if I forgot anything please let me know. With the summer months coming I would like to get this working. I didnt want to take it to a shop yet, figured I would come here and see if you can help me. I dont know the most but I do know a thing or two about fixing things.

 

You said it's not spinning- does that mean the outside pulley or the clutch itself is not engaging? You can turn the clutch by hand (the inner part of the pulley), if it moves you may have to replace the clutch, if it won't move then the compressor is locked up.

And by the way 170psi is HIGH, I think they are supposed to be somewhere between 40-50psi.

 

The outside is spinning, thats the serpentine belts path. When the truck is running the inside does not spin, so the clutch is not engaged. When the truck is running and AC on the clutch will turn but only when I move it. I used a flat screwdriver to turn it while the engine was on. It only spins when I push it, so its no free spinning.

I wanna say it was 170 but that could be wrong. I filled it till the needle was in the green on the gauge the bottle had on it.

 

You may want to empty the can into it. Usually the clutch won't engage if there isn't enough refrigerant in it. Same thing was happening with our saturn last year. Emptied a full can, then hooked up and started another before it ever engaged.

The gauges on the refill hoses aren't very acurate, you would be better off with an actual pressure gauge. That being said I never use an actual gauge, just empty an entire can in it when the air gets warmer than I like.

 

Just wanted to update this. Got off the phone with a friend who know more than I thought and well I messed up big time. I was filling it with 134a+ but the condenser needs R-12. I was told to disconnect the clutch just in case. So I will need to flush it and retro fit it to 134a+ anyone know about what that can cost?

But upon adding 134a the clutch finally stared and was producing cool air. So that was the problem now I just made another problem damn guy at AutoZone gave me the wrong stuff, how was I suppose to know? That was why I asked him first.

 

If you were able to use the quick connect on the refill hose then someone already switched it over. You wouldn't be able to hook up the R134a to the R12 port. I believe you are now good to go, may take another can to get it ice cold though.

 

That's right. You can't add 134a to an R12 system unless it has been converted. You need a license to buy R12 and the auto parts stores don't carry it or the equipment to add it anymore.

 

Might i add, over filling the a/c system is very bad. If there is any weak point anywhere in the system you will surely find it. There is two sections one high and one low pressure. Check manufacturer PSI ratings for your truck and keep it at or a little above the recommended pressure. Correct me if im wrong but i worked at a shop through a summer and pretty much all i did was vac-fill a/c's and replace compressors.

 

You are right, over filling will cause damage. Most older systems leak already so it would give the excess a place to exit the system at. In my eyes dumping a can in when the air gets too warm for my comfort (maybe $10-$15 every few years) is much cheaper than having it serviced ($75 min. for just flushing and refilling, add more for stopping leaks). I will always recommend that someone use the proper gauge to check pressure but as for myself- that thing is going to take the whole can and like it.

 

Check your pressure switch. Its on the receiver/ dryer. That's the metal bottle. There are 2 words going to it. The wait h turns the pump on and off to maintain the proper pressure. Jump the wires for a second. Don't leave it this way or you will blow the relief valve or something more permanent. The clutch should engage and start pumping. Now for everything else wrong here. Refrigerant attracts moisture and air pockets reduce efficiency. If there is a slight leak, seepage through the old seals and hoses or if its been opened or drained you have water in the lines. To eliminate it you must pump out the air and create a vacuum. Water boils at low temperatures in a vacuum so it will boil and be pulled out by the pump. Then you can charge the system with new refrigerant. Next you really need to know what refrigerant is in there. Different types dont mix and as stated they use different fittings just for that purpose. There is a tool to check the type of refrigerant in the system. Finally you need a/c oil (pag oil) in the system. Again the right amount and the right kind and they don't mix. It sucks to say it but a/c is one if those things you really should take to a shop if you don't know what's in there. They will likely drain everything and flush it then refill it properly. I would go ahead and replace a few pieces like the pressure switch and the reducer then take it in for a service. On the up side it will be done in a short time and your air will be ice cold. I did mine in the shop when I was training and I didn't think it could even get that cold. Literally a few degrees above snowing. Of course I tweaked it a little.