Okay so here is what I found. Before I did anything I measured the temperature from the drivers vents 47 degrees Fahrenheit while the passengers where 16 degrees warmer at 63 degrees on a 86 degree day. I put between 3-5 oz into the system(I'm guessing I did not take the time to weigh the can). I went up 2 degrees on the driver side so running about 49 now while the passenger vents came down to 56. From this I would say that yes the system was low but I have now either added slightly to much or because presumably there is also now air in the system that its not running as efficiently as perhaps it should. Curious what people think about my theory of air in the system. I feel pretty confident because I lost 2 degrees on the driver side that its slightly over pressurized just wondering if air in the system is making it less efficient.

 

How did you introduce the new refrigerant? The auto store cans I've used are are pretty forgiving as far as preventing you from overfilling. i was barely able to get in the green last time I did it and I'm 39°F on the driver's side and 44°F on the passenger side at 85°F ambient. These temps are while moving tho and rise considerably while sitting at idle.How do you think you got air in the system?

 

I used a 12oz can with the basic T tap and gauge to add to the system. Gauge indicated slightly low in the green when I started still in the green just bellow half after a few bursts. This gauge does not have a dial that allows to adjust for the temperature as others I have seen do. My assumption on air in the system is that if refrigerant is leaving the system over time than its possible air can also be entering the system. ahab, which vehicle are you taking those temperature readings from?

 

I would say that as long as there is still some pressure in the system, no air will be able to leak in.

 

I would have NEVER thought that low Freon would cause one side to be colder/warmer than the other. Good to know, thanks for sharing!

 

I believe your original post is on the right track. There are two things here: what is the lowest air temp your system is producing, then where is the cold air going?
To get an accurate temperature reading, I would drive the car for about 20 mins on the freeway. This gets your AC pressure up and will ensure it's pumping out the coldest it can.

If you're NOT get colder than 47° then you likely need to charge your system.
If you charged the system (adding refrigerant) and it starts to get WARMER (i.e. 49°) then stop, as you have likely overfilled it a bit.
If you can't get it colder by adding some refrigerant, I would take it to a shop.
There are several things that have influence on getting air cold, there are some 'consumable' parts in your system that you can replace (txv valves, drier, and even the condenser).
I would probably try the simplest thing first at this point: recover refrigerant, pull a vacuum on it (verify no leaks and remove an atmosphere that might be in the system), and just re-charge it properly.

I personally thing the issue regarding driver side vs passenger is a blend door issue, and no other voodoo.
Good luck!

 

yeah it’s pretty odd. I’ve been working on VW, Ford, and Hondas for 20 years in shops and have never seen that before.

The only thing I can think of is the condenser in the cabin doesn’t get cold across the whole face when the Freon is low and the driver side is vented to the coldest side of the condenser or something

 

For what it's worth, my windshield continually condenses on the outside when I run the air in mild, humid temps because cold air is going out the defroster vents so I know at least some of my flappers aren't sealing well. The driver's side being much worse than the passenger side. That said, I still get the temps quoted above when the system is charged correctly.

If you filled the system with a can tap and didn't let positive pressure out of the hose before connecting it to the low side port then any air that was in the fill tube would have been introduced into the system. That's not good for it, as oxygen is caustic to AC systems and depending on the amount will surely damage components over time. That's why I suggested the can with the gauge at the auto store rather than a DIY fill, simply because it's more foolproof. If you do have air in there then as suggested you should have the system discharged, replace the drier, pull a vacuum to ensure it doesn't leak (or find out where it does if it won't hold) and then have it properly charged.