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Heater And Blower Help

00'CherokeeXJ

NAXJA Forum User
Location
America
So here is my dilemma. It is 35deg out and my heater only blows semi-warm. Id say the air coming out is mid 60 deg. Im not familiar with the heating system so somebody help me figure out what could be wrong. Also my A/C - Heater control panel is broke i think. It only works on the defrost vent. If i turn it to any position, say feet and face vents it still blows out the defrost vent. So im not sure if this has to do with my first problem above or what?
 
Is the T-stat working? If it is stuck open the engine never gets up to temp, thus luke warm heat. Your other problem is a vac. leak. Check the vac. ball in side the front bumper on the pass. side. Make sure the hose is plugged in & the ball itself is not cracked. Check the hose for breaks all the way to the firewall. JIM.
 
Always start your threads with the BASICS--year/engine/etc., it saves the rest of the kids from having to ask each time.

1984-2001, lots of changes during that production run.

ILLXJ is right, the lack-of-vacuum default position for the vents is DEFROST, so you likely have issues there.

If you drive the vehicle for 20 minutes, until the engine is fully warmed up, then pop the hood and being careful of moving parts--flesh and clothing do not play well with moving engine parts--grab the upper radiator hose. If it is uncomfortably hot to hold, your thermostat is likely Ok.

You may or may not have a coolant control valve (what the heathens call a temperature control valve) that is vacuum operated. This depends on the year--oops, there is that whole BASICS thing again. That valve is vacuum operated--seeing a common thread here (defrost vents/lack of vacuum/coolant control valve/vacuum operated)?
 
Alright you guys are awesome. I learn more about my jeep everyday. I got up underneath that plastic wheel well crap and found out that that hose going into the ball wasn't even connected! It was literally a 30sec fix. I popped it back in and it works now! Now I just need to get my air hot again and ill be toasty in no time.
 
Well i just bought a new thermostat 195deg. Ill be putting that in tomorrow. If my heater still only blows mild warmth then ill have to trouble shoot from there. And too whoever said to hold the radiator hose...I drove to work which is about 15 min and the hose was bearable to hold so im hoping this thermostat will fix that.
 
i was thinking coolant too. if its not low then what does it look like. if its all gummy and nasty that could be ur problem. it was with mine. i tried to flush mine with that stuff u buy from autozone "super radiator flush'' but it didnt work well so i went to a pool supply and got some muriatic acid and put it in the radiator and let the car idle for 5 min. when i pulled the petcock on the radiator u wouldnt believe ho much shit was in my ssystem. and i can say that it helped with the over heating issue too. ran about 10 degress cooler. no b.s. i also second the vac contolled heater valve its by the fire wall. just check it to make sure it isnt all shot out. it only cost like 17 bucks at autozone.
 
x2 flush your heater core. I would try unhooking the hoses that go to it. With a garden hose at low pressure, let water flow through them for a while.
 
No heater control valve on the 97+. Coolant flows through the core at all times. Flushing the core isn't a bad idea though. Do you know when the coolant was last changed? If not, it's probably time to flush and refill.
 
Hah well...we flushed it this summer but it is by no means clean. I'm on my second engine and it was overheating this summer so we flushed it out with a garden hose for a good 20min and rusty brown ass water came out the whole time. The coolant bottle was full of rust, oh man it was bad. I should have run it till it was clear but idk how long that would have took. If it weren't 30deg out id flush it again but its so frigging cold that i don't even want to bother.
 
Hah well...we flushed it this summer but it is by no means clean. I'm on my second engine and it was overheating this summer so we flushed it out with a garden hose for a good 20min and rusty brown ass water came out the whole time. The coolant bottle was full of rust, oh man it was bad. I should have run it till it was clear but idk how long that would have took. If it weren't 30deg out id flush it again but its so frigging cold that i don't even want to bother.

Ok, a proper FLUSH of an automotive cooling system involves CHEMICALS beyond H2o.

Those fifteen minutes flushes? Close to worthless.

Get the RADIATOR CLEANER that you put in and drive for 3-6 hours. Prestone, Zerex, others. Follow the directions.

Use a mix of distilled water and ethylene glycol--50/50 for late Fall to early Spring, 30 ethylene glycol/70 distilled water late Spring to early Fall.
 
Alright well i guess im going to flush my system again. I'm ready to go outside and get cold, muddy, and wet since its raining/ almost snowing lol. I do want my system to be perfectly clean so I want to do it right this time. So how do i flush the heater core, and what are these flush T kits I keep seeing and where do they hook up?
 
Personally, I don't care for those "T" kits, seen to many of them FAIL. There was a rash of bad ones and supposedly Prestone--the most common--fixed the design or started using better materials, but I still don't like them.

As for flushing the heater core. Two hoses to the heater core. The hose that runs from the thermostat housing is the heater core "IN" hose. The other hose goes back to the water pump and is, of course, the "OUT" hose.

Back-flushing the heater core is considered the best way. You can do this by switching the two heater hoses where they enter the heater core.

When you run the RADIATOR CLEANER through the system, with those heater hoses reversed, that should clean the core pretty good.

Good luck.
 
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