megankalu

I have a 1999 Jeep Cherokee Sport - I turned on my heater this morning and I have no air and no heat coming out. Then it smelled like something was burning. The morning previous, we had an ice storm and it was so thick on my windshield that i broke my scraper to try and get through the ice. So i got a pot of hot water (i know, not too swift) but i was late for work. I drove to work and the eater was working. As i shut off my car, the heater made a funny sound. Then when i got back in after work, 7 hrs later, I turned on my heater but no air or heat came out. I noticed all the small vents at the bottom of the windshild under the wipers outside the vehicle had 3 or 4 inches of ice (I guess it was all the water I poured on the windshield in the morning and it froze solid). So, could I have done something to the interior heater and fan by pouring the water on the windshield and it froze on those small vents? Or could it be something else? I thought it might be the heater core, but someone said if it was that, the fan should still work blowing cold air, but that doesn't work either. I'd really appreciate if someone might have another idea before I go purchase a heater core. Thank you in advance.
Megan

deepdiverterry

Hi Megan,
consider yourself REALLY lucky you didn't crack the windshield with the hot water ! Anyhow , the water might have leaked into the heater fan and froze, locking it up. If you have any kind of electric heater , I would put it into the Jeep and let it run keeping in mind not to set it on fire ! That might thaw things out. Be sure the heater fan fuse is OK. I like to try the simplest things first...keep me posted and I'll try to help out.

megankalu

Thank you Terry for your quick reply. Yes, i've been told that i'm lucky i didn't crack my windshield... oops! Anyways, I found the fuse box under the dash by the passenger seat, but it doesn't indicate anything where the fan fuse would be. Any ideas? I would assume it's probably a 25 amp? We'll start there first. Someone else said to take it to a self-car wash and take my time and start washing along the firewall with hot water for a few minutes and see if that thaws it out, because they think i froze the fan too. But it's still -27 below outside, so my vehicle doors and everything will freeze again. So i don't think i should do that.But i'll try the fuse first if i can find it.... thank you in advance Terry.
Megan

CrazyWJ242

check the coolant level in the radiator, make sure its filled, as well as the reserve tank... you want to use 50/50 mixed antifreeze and water... if you use just Antifreeze, sure its not going to freeze, but you wont get heat either... OK now thats all topped up, check the lines going into the jeep (assuming 4.0L) its the two lines running along the valve cover from the waterpump to the firewall.

If this line is warm (when the engine is running) then you have coolant going into the heatercore, the return line should be roughly the same temperature IF the fan isn't running

If no air is coming out, (the fan doesn't turn on) you may have a dead blower... which can be a pain in the butt to replace, i dont know if its as bad as mine, which is completely disassembling the dash... BOTH SIDES...

but if your heatercore was leaking, it could have killed the blower motor, and you have to fix both... it happened on my XJ States side, but then i just didn't use the heater inside the jeep lol

megankalu

Thank you to the postings and I really appreciate your help. I've actually implemented from both the postings. Terry, I as i said earlier, although i would have tried the car wash thing, i can't because the weather is still real cold, -28 last night, so everything would have froze. I don't have a garage. So then I tried the heater thing and left it on for the last two nights. i put it on the floor of the passenger seat and pointed it towards under the dash. Then I tried the fuses and I also followed the lines from the waterpump to the firewall and one was warm, the other cool. So then i remembered something i did a couple of months ago. I bought a jug of antifreeze and i poured the whole thing in the rad and reservior and now it explains why i wasn't getting too much heat inside. I thought i had to change my thermostat, but if putting too much antifreeze in is the reason i didn't have too much heat, well, then today i'll try putting in half and half. But i'll continue to try all your ideas and see if it helps. I think that until our weather starts warming up a bit things will stay frozen (if that's the problem). Again, thank you very much for the tips.
Megan

CrazyWJ242

well if one of the lines is still cool, and the fan wasn't running on full tilt, the coolant is most likely not running thru the heater core, and you just need to flush it out...

basically disconnect the hoses from the water pump, and hook them up to the garden hose and cycle the water thru both lines to see if you can free it up and get coolant flowing normally...

once water flows thru in either direction, hook it back up to the water pump and pray for heat!

deepdiverterry

Hi Megan , sorry I didn't check the posts yesterday. Hows the progress ? One of the other posts siad about a 50/50 mix of antifreese but I'm not sure why he thinks just antifreese will make it not blow heat. Anyhow, did you at least get the fan blowing ? The cover of the fuse panel might have the location/amp size of the fuses. Low antifreese level, the first thing you'll notice is your heater will start blowing cold air as no coolant will go threw the heater core. Seeing as nobady likely stole your coolant you probably have a leak. If your level was OK check your heater core lines for temp. as the other post says. You did say in your last post one was hot the other cold. Flush out the lines and make sure your themostat is letting the engine get up to proper temp. Keep me posted !

CrazyWJ242

Too high of a mixture of Antifreeze will not get as hot as a 50/50 mixture of antifreeze and water... if she had pure antifreeze in her system it would take a looong time to get heat... and she wouldn't get too much of it...

even then ideally you should have distilled water in your coolant system, not tap water... but really its not a big deal, its just distilled works best

quick check on the thermostat, big hose from the waterpump should be nice and hot when the jeep is up at operational temps.

deepdiverterry

I was under the impression that "antifreeze" besides all the corrosion protection etc. that is gave you a comfort level of not boiling at 212f as water ....water that is not under pressure as in the cooling system. It intreged me so much and I didn't have much to do today I did a test. I took three pots of stuff , one 50/50 antifreeze and water one 100% antifreeze, one just water. I turned all the burners to medium. As I only had one thermometer they all seemed to reach 180f in the amount of time it took to cool off the therm. and stick it into the next pot. The 50/50 boiled at 230f ,100% was 219f and the water was ,yup 212f !!
Anyhow, like I said , I didn't have a lot to do today. LOL