Where is the A/C low side recharge fitting - Heating & Cooling

the correct one should be smaller, and your recharge hose should be only able to connect to it. the smaller fitting is the low side, and the larger fitting is the high side. recharge only to the low side. the high side is used by technicians with elaborate ac manifold guages to monitor success. these guage kits can be bought at harbor freight for about 55 dollars,and give a better recharge,as you can regulate pressure as not to overfill, which lessens the cooling

Typically the fitting on the recharge kit will only fit on the low-side line. Here is a good website that explains the recharge process:
http://milkyourmoney.com/2009/05/27/diy-how-to-recharge-your-cars-air-conditioner/

low side should be on or near the accumulator whch is on passenger side

the recharge kit will only fit on the low side fitting which is the smaller fitting on the larger lines/hoses. If it doesn't fit on the fitting you have tried than you are probably trying to put it on the high side fitting which is the larger fitting on the smaller lines/hoses. I think the low side fitting is on the receiver drier on this model which is the canister looking thing back by the passenger side of the firewall.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

you always recharge on the low side. The low side is the larger lines/hoses. the high side is the smaller lines/hoses. The low side fitting on the a/c system is smaller than the high side fitting. this is so that the low side and high side can not be hooked backwards accidentally. The fitting on your can of recharge will only fit the low side fitting on the a/c system.

To find the low side fitting on your a/c system to recharge it simple follow the low side line/hoses (the larger ones) until you see the fitting which usually has a plastic cap over it. Follow the instruction on the can of recharge and you should be good to go.

If you have any other questions I'd be more than happy to answer them.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Sometimes it is in the back or side of the engine bay, but I usually find them underneath the engine. The fitting for yor recharge kit will only fit the low pressure side, should have a blue cap.

The low side has a black cap covering the recharge valve. Even if you tried to place the recharge hose on the high side, it will never fit and is designed for the use of a totally different hose fitting.

The port on the accumulator is the low side. The high side port is smaller than the low side. The low side port is the one that gets cold when the compressor is running.

The low side connectors are diffrent from the high side, you would not be able to connect it anyways. The high side has a bigger port that the low side, and it would not fit anyways.

The low pressure port on the 2003 grand am is actually behind the engine, near the firewall on the passenger side. Good luck getting your hose down there though, I ended up buying an extension hose.