I have wondered about the fan clutch contributing to a lack of heat issue. My fan seems to spin when the truck is running. I am sure it drawing air in takes away heat that my heater core could use.

 

I've got the same problem.

Here's a question - I pulled the radiator cap and ran the truck for about ten minutes so that the temp gauge on the dash read normal 200? Anyways, when I went to touch the coolant in the radiator it was room temp. But the truck never overheats. And this just started the other day - been fine up to this point.

One thing, I did let the coolant get down in the reservoir for a week or so - I figured topping it up would cure my (non) heat problem but no luck.

Could this be the thermostat ?

 

if it is then your temp reading doesnt make sense?

 

I was convinced that i needed a new heater core,so today i took my dash out and checked the core and it was hot but not coming out of the vents, so i fooled around
with the cable the works the blend door and it was jamed. so i got it free to move
all the eay to hot and i have heat now! thank god it getting down to 20 tonight

 

Hey Scott - did you take the whole dash out or just the top surface to get at that heater cable ?

I'm thinking now that is what is wrong with mine as well. The top radiator hose is hot, both the heater input & output hoses are hot
- plus the heat was working perfectly on Thanksgiving day, then the very next day it was broke - like someone flipped a switch - and there is no coolant leaking anywhere.

Scott - any tips on removing the POS dash I would appreciate. What a job that is, looks like a bomb went off inside my truck.

 

I started with taken the lower dash support bolts out that are behind the kick panels on each side,some people take the panels out but i just pulled them to the side. then there is the panel with 3 bolts under the column that had to come off then i could lower the column then i loosened the top dash bolts just under the windshild and that gave me enough room to get my arm in there to check out the plastic arm that controls the door. mine wasnt going all the way over so i just played with it and it started working. the previous owner had replaced the core and i think they must have jamed the door and or cable. yea it does look like a nightmare when its all half out.

 

I wanted to update this because this problem is getting a bit strange.

So I have minimal heat in the cab, pulled the dash and the blend door cable looks fine. So I go back to the heater hoses and the first time I checked these the inlet hose to the heater core was nice and hot, and I 'thought' the outlet hose was hot as well, but I think I grabbed it too close to the water pump and now I see that it is not very hot at all.

So I take the 500 posts here telling me to back flush the heater core, so I put a garden hose fitting on it and flush it both ways, forward and back and the water just POURS thru the heater core, just like it was coming out of the hose, and no gunk coming out either.

So if the heater core is NOT plugged then the only thing left is whether or not coolant actually being PUMPED thru the heater hoses. So I pull the heater core outlet hose from the pipe where it goes on the water pump on the driver's side, and I add a short length of hose there and fill it with water and I fill the outlet hose with water as well. If the water pump is pumping coolant and the heater core is not plugged, then water should get sucked into the pipe on the water pump and at the same time it should come shooting out of the outlet hose from the heater core.

nada. nothing. zip.

The water in both hoses just sits there like the water pump is not even there. And actually when I pulled that short section of test hose off, there was some coolant very slowly pulsing OUT of the pipe on the water pump, when it should have been getting sucked in post haste, according to my understanding.

But the engine never overheats, and I can see the temp drop 20 degrees or so when the thermostat opens up and the top radiator hose is HOT.

So I don't get it. It appears that water is NOT being pumped thru the heater hoses, but it IS being pumped into the radiator hose.

And no leaks, truck temp gauge runs just like it always has, and no noises off the water pump.

???

 

I am having the exact same problem with my heater, except that I just replaced the water pump due to a leak, and the thermostat since I had everything apart already. I flushed the heater core, and it takes all the volume and pressure of the water hose on high.

When the heat is on low it is pretty warm, however after turning up the fan it cools off quite a bit to just faintly warm.

I think I will try the CLR treatment tomorrow and report back to see how it goes.

 

That has been my suspicion all along. I have been too lazy to hook up a clear section of hose to see just how well it flows.

 

I started to replace my core in Oct using a Haynes manual. What a piece of CRAP those manuals are. 2.5 hours later and I was still removing skin pieces. Fed up and pissed off I put everything back together and ended up short on screws (I'm thinking the previous owner had the dash apart and failed to put all screws back in...like I always do ) anyhow several google searches later and I came found a nice PDF that "I think" will be a tremendous help. 5-speed vs. Automatic...Can't be that much different.

URL DENIED!

Soon as it warms up...or I find a garage (w/heat) and a spare Saturday (yeah right) I might tackle the replacement again.

edit...I thought that might happen.
do a Google search for "dodge heater core replacement instructions" and look for *Instructions* Complete.