I have a 1999 jeep grand Cherokee. When I turn on my heat I do not get hot air just cool air and also the floor on the passenger side is getting water from somewhere

Sounds like a leaking heater core

Ya. Pull back the carpet. You should see a green streak of coolant running down the lower part of the fire wall. You can also remove the seat, it's easy to do. Then you can pull back most of the carpet to vacuum up or mop up the coolant.

You have two choices. Remove the hoses going to the heater core. Cap them off where the come out from the water pump. Then of course you will have no heat , and no leak either.

The other is to replace the core which requires removing the dash. Not exactly a DIY project for the weekend warrior. Expensive to have a shop or dealer do.

My understanding is that now, newer vehicles off all makes and models are made with cores that are easily accessible. Labor costs are way lower, but the new cores are very expensive. In your case the new core is about $50.

They get us coming and going. One way or another.

Yea sounds like your heater core is toast. Very costly for a dealer or shop to fix, as mentioned above, it requires removal of the dash(like most older vehicles).

However, depending on how mechanically inclined you are, it's not the worst job in the world. I'm sure there are some good write ups for this. I have done a few on different vehicles, while they all are a PITA, it still beat the cost of a dealer/shop.

For a shop to do it your looking 1500 bucks or more.

Yup. BTW, ethylene glycol destroys your liver. Not good to inhale it.