2001 Dodge AC
 

So I have a problem with my AC. It will run cool then just stop and blow air.... After a while it will run cool again. I checked freon and then it runs its around 75 PSI and when it just blows hot it jumps to 110 PSI (this is the low port reading.) Any help would be nice its hot in Texas, Thanks :c:

75 is way too high of a reading when the compressor is running, 20 is a better number. What's the high side doing? Is the condenser plugged, or not getting enough air flow?

2001 Dodge AC
 

No I dident have a high side gauge... And I just cleaned the coils with coil cleaner and a coil brush

2001 Dodge AC
 

I'm thinking about just getting all the old freon out and doing a recharge at a shop... I done have the tools to do it right now

2001 Dodge AC
 

Also miss red the compressor on psi it's 45 not 75 it was dark last night

45 is good. 20 would actually be too low. It sounds like the compressor is turning off. There are a few things that can cause that. The low pressure cycling switch could be going bad. Some systems have a high pressure cutoff that protects the system against too high of head pressure. Not enough airflow through the condenser could cause high head pressure which would cut it off until the pressure drops. Some vehicles have the ac controlled by the pcm and other engine malfunctio9ns tell it to turn the compressor off. I don't know off hand if that is the case with the dodge. A bad fan clutch can cause not enough airflow.At least this gives you a list of places to start looking.

2001 Dodge AC
 

Yea I thought so I'm going to evac all the freon on it this weekend use a AC cleaner with some
Shop air to clean it all out then reoil and add some new freon and see what happens... I bought the truck from a company I work for and I know all kinds of stuff has been put in there

If leak detector die has been added too many times it could be over oiled since the die is carried in oil into the system. Too much oil can also cause high head pressure and cooling loss. I usually use acetone to flush the systems but you have to be careful to blow out all the residue and vacuum the system for and extended time to make sure there is none left before recharging the system. Regular flush solvent is more forgiving about residue left but it is more expensive. I never flush through the compressor with anything, Only the condenser and evaporator. I built a catch system so I can capture the acetone for distillation and re-use. If using acetone it is also wise to keep in mind that it is flammable so sparks of flame around it is a bad thing.