The A/C gets warm when stopped at lights

Hello again.

In case you're having an issue with the A/C compressor here is a tutorial for you to view on how to remove and replace:

https://www.2carpros.com/articles/replace-air-conditioner-compressor

You will need to remove the serpentine-drive belt to be able to gain access and remove the ac compressor. Here is another tutorial showing how to remove and replace the serpentine belt:

https://www.2carpros.com/articles/replace-serpentine-belt

After you perform this repair you will need to vacuum and recharge the system. Here is a tutorial showing this as well:

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

I've attached picture steps below showing how to remove and replace both the serpentine belt and ac compressor on your Dodge Ram. Hope this helps and thanks again for using 2CarPros.

Danny-

Have you checked the system for a leak? If the system is leaking then it's understandable to add 4 cans of refrigerant. If the system is not leaking and added 4 cans then it's possible the system is overcharged and still not working correctly. Here are a few tutorials for you to view on theory and testing the A/C system:

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

Hope this helps and thanks for using 2CarPros.