It was kind of cold with no heat when it is about 28* outside. I have a 97 jeep cherokee, it blows cold air but not hot and my thermostat works. My husband tells me it is a vacume hose unplugged or bad. Can you guys help me out. It will be another cold am and I would like to see if I can find this vacume hose if it is the problem.

I'd pull the control panel out and be sure that everything is connected properly. When you switch the temperature control from hot to cold you should be able to hear a soft "whoosh" sound or a thunk as the door moves to allow the hot air through. If it's like my TJ then the temp control pushes/pulls a cable and when mine got crimped it would bind and not allow me to switch to heat. That's where I'd start with it.

Might try flushing the heater core out.. i've seen them clog alot this time of year when people accidently mix the wrong type of antifreeze.

Just take a hose and use light pressure to see if it flows through ok. Don't stick it on there at full water pressure though.

What makes you think your thermostat is working? When your engine is running, does the temp guage read 210, or something lower?

What your husband is talking about could be one of the hoses underneath the dash that closes the vents to let cold air in from the outside. Its not fun, but you can get under there and manually close it off. Just trace the cable/wire that controls the hot cold temperature to where it meets into the heater duct work, that should be the vent that lets in the outside air. Make sure its closed before you start pulling apart thermostats etc etc.

Hows your oil look? Is it clean or milky?

Little Jeep-I look at the temp gauge when I go home and to work tomorrow.

The Black Sheep-clean but I do need an oil change soon. Is this tube under the passagner side.

Rooney77-I do hear a thunk sound but then again I just get cold air. I have no clue where the control pannel is even located.


I sure I can figure this out but it will be friday afternoon. I go to work in the dark come home in the dark.

:laughing:

What makes you think your thermostat is working? When your engine is running, does the temp guage read 210, or something lower?


It reads lower

It reads lower

I am having same issue with one of my Jeeps. During Summer, I replaced water pump, thermostat, hoses, etc.,. At sametime, I back flushed the heater core so I know I have good water flow thru it. Thermostat I put in was a 185 degree which was fine during hot Summer, but now I can drive all day and never get temp to 210. I am going to replace my thermpstat with a 195 degree to see if this takes care of the problem.

A cooler thermostat might help, it should still have something though.

How old is the heater core?
How much lower then 210 is the temp reading? Take an guess
Your dipstick checks the oil, check that and also underneath the oil fill cap
Maybe your thermostat is stuck open?

Id probably go pick up a stock thermostat and just replace that, they are cheap, and fairly easy to change.

After that, if your coolant is clean and your coolant system is full (Low coolant will not give you heat either) then chances are its just a tired heater core. Which sadly is a pain in the ass to get to.

In older motors, the problem could have been coolant level too low... such that the coolant is not flowing through the heater core. I assume this could happen on a '97, but if so I'm surprised nobody's said to check your coolant level!???

In older motors, the problem could have been coolant level too low... such that the coolant is not flowing through the heater core. I assume this could happen on a '97, but if so I'm surprised nobody's said to check your coolant level!???

Post #10 at the bottom.