Q: When a/c was on, steam from under hood and a/c went warm on a hot day and on another day came out cool for a several minutes

The source of the steam should be the first thing repaired. It is highly probable that once the leak is repaired, the A/C system will begin to work again. There are two fluid sources under the hood that can create steam. They would be coolant and A/C refrigerant. The description you have given suggests the refrigerant is low in the A/C system and this is also consistent with the steam from under the hood. In addition, if you had a coolant leak, your car would most likely be overheating and the leak would be getting worse the more you drive it. It’s is very rare for a cooling system to leak and then stop. The A/C system however under goes a series of pressure changes as it begins to produce cold air that could easily create a leak and then turn off as a result of the sudden pressure drop.

I recommend the following inspection to help you out; AC is not working inspection, to get your air conditioning system back working again.

Good luck!