A/C working sometimes usually when temperature is around 70 or below

How did you confirm the system was not low? Did you check the pressures with a gauge set? If not, then we don't know for sure that it is not low.

The complaint of A/C not working when it is hotter outside is normally caused by a low charge in the system. This is why we need to start with checking the pressures.

If you don't have a gauge set shown in this guide then you can rent one from a parts store that has a tool rental program. Just hook the gauges up and turn the engine and A/C on and tell me what the low and high side read when the compressor is on and off. Once we know the pressure and the ambient temperature we can determine if it is low. If not, we can move on. However, if it is then we need to evacuate and recharge the system to ensure it is properly filled.

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

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

Let me know what you find and we can go from there. Thanks

Okay, thanks. I will give it a try. all I did so far was use one of the refilling gauge things and it said it was in the full section. but if you are talking about the high and low pressure readings i can see if i can get one.

Yes, you need both pressures when the system is working. That can tell a lot about the system and not just if it is charged. Your description sounds like a low charge or possibly a compressor that is getting weak. The double gauges may show the issue.