Jiblet

Are you getting too little heat or none at all?

If you start your engine cold and put your hand on the upper radiator hose you should feel it go from cold to warm when the thermostat opens. Should only take a few minutes at idle, less if someone gently revs engine for you.

You can also feel the heater core hoses while running your heater. If only one (or neither) gets hot, then the core might be clogged.

JeepaRoo

as others have said, the heater air temp is controlled by a couple things..

1] coolant temperature.. if your temp gauge never reaches the middle you likely have a stuck-open thermostat.. that will reduce heater performance..

2] if the engine temp is reaching temperature yet you still dont have 'burning hot' air there coukd be other issues.. it has cable driven air-mix door.. this door determines how much of the air from your vents comes directly from outside, or how much of the air is sent over the heater core for warming.. if that cable breaks or slips, then you will have poor heater performance.. that cable connects from the "warm...cold" dial to the air-mix door on the HVAC plenum behind the glove box..

3] if your heater core is partially plugged up you will have low coolant circulation through the heater core.. in this case you will have to remove and flush it or replace it...

4] the role the A/C plays in winter driving is simply for window defogging.. in humid rainy or snowy conditions, use of the defroster or pressing the 'A/C' button will dehumidify the air before it goes into the cabin.. the A/C compressor will operate down till about 30-33 degress outside.. any colder than that and it is disabled...


I should also add that im about the coldest body on earth in winter.. I set my house heat at 78 when its cold like it is now (in the teens / 20s).. yet I still drive my JK with my coat off and short sleeve shirt on.. and still have to turn down my heater.. and my 2010 had a hotter heater than my 2013 does...

-Christopher

Breitling

How cold it is outside? It happened to me that when switch for air direction stopped between positions, air flow got decreased a lot. Move it a little until it clicks on right position if it is not. I could compare with my other cars, Wrangler with hotheads installed is not much worse than one with regular roofs on heating or ac.

capjim

def check the thermostat cause you can boil noodles on my heat vents....sometimes I wonder if the vents are going to melt....best heater of any vehicle I've ever owned

jk_sea

As others have said, sounds like there's a problem with your heater. A Jeep running at operating temperature should be able to bake you out of the cabin when the heat is turned all the way to "hot."

You might want to fix any leaks and recharge the A/C if you have a wet season in the spring, or a hot summer. The defrost setting uses the A/C pump to dehumidify air, can help dry up steamy windows when it rains. And, of course, it keeps the cabin cool in the summer. If it's not working, remember, it didn't just run out. There's probably a leak somewhere. Recharging it will just let it all leak out again, if there is one.

Michel347

Even with this outside temp this morning, I removed my coat in my JK.

Rdub18

It is cold here! Single digits and teens most mornings. Was 25 yesterday driving to work.

Thanks for all of the ideas so far!

JMcD

I agree 100%! This thing cranks the heat out!

scotiez

I wish it was 25 degrees here. I'm in North Dakota and the month of December has been brutal. Most of the month the temps have been below 0 F, My JK has a soft top and the heater cooks me, Gets real hot and fast.

FDHog

I run a soft top all year long, and I can't turn my heat up all the way, it's just gets too hot, and that's even in 20 deg weather. Something's wrong.