heat doesn't get hot antifreeze is full, new thermostat, and doesn't run hot temp runs about 180.89cherokee

Model, Year? Probably a clogged heater core, back flush it and see if that helps.

that is about normal you have to figure it is winter now temp outside is much cooler. meaning when the cooler air hits your radiator with the fan blowing on it at that the coolant will stay at a lower temp.as far as the heat inside you may have a clogged heater core or bad heater switch it is hard to tell without more information.what year is your jeep,did you flush the entire system and so on.

not sure youre vehicle, but my buddy's tj had a air bubble in the heater core. we had to loosen the top heater hose (be careful of course its hot) to vent it.
on cj's the heat just sucks without a blower upgrade.
could have some crap in the heater core, might want to flush the whole system.
sometimes leaves and stuff can get in the plenum and block air.
i know you said its full, but the heat is the first thing to go as level drops.
Josh

or go find flyin cowboy and trade jeeps
<img src="/forums/images/graemlins/lol.gif" alt="" />

I have a similair problem. If i just open up the heater door and dont turn on the blower it heats up great. But as soon as i turn on the blower the heat goes cold. I know once it was the air mixture door on the heater assembly. It had fallen out of place. <img src="/forums/images/graemlins/kewl.gif" alt="" />

two things.

well, okay, three....

Need more information on the year and such...
Additionally, is their air coming out of the vents, is it clean smelling or musty?

If you have something that is equipped with one of those cabin air filters, it could be a problem.
If you have a traditional air intake system for your cabin, you may want to pull the heater core out and make sure it is not clogged in the inside, as well as the outside. May have a bunch of dust, environmental goo ro whatever blocking the flow.
Lastly, you say the coolant is full. Are you referring to the over flow bottle (plastic, semi-clear thing) or the radiator itself? The plastic bottle is useless as far as telling how much is in the radiator. Try pulling the radiator cap off, starting the engine and keep an eye on the level while it is warming up and when it has reached mormal operating temperature. If it drops more than 1/2 inch below the bottom of the neck, you aren't running on a full system.

Okay, let us know so we can get a better idea as to whats really bothering you.

guys he said it was an 89 cherokee. it could also be a faulty cable causing the heat doors not to open