I have a 94 Ram with the 5.9L engine. The heater just doesn't seem to be blowing out as hot of air as used to. The fluid level is good. I think my temp gauge is broken because it doesn't really move. I even changed out the themostat and that didn't help. I felt the radiator hoses and they feel hot. It feels like coolant is circulating through them. I just don't know what to try next. It blows out warm air and when you give it more gas it gets hotter. Any ideas of what to check next? Thanks.

 

try backflushing the core by disconnecting the hoses at the firewall and blasting water thru it, maybe a little cleaner also.
make sure the blower motor is getting up to speed and the blend doors are functioning correctly (if not probably a vacuum leak)
also make sure your mix is 50/50 or the effeciency of the system will drop like a rock. even though you replaced the thermostat replace it again and make sure its a 195F. good luck.

 

Without even going into half of what the previous poster wrote, I'll tell you right off that the thermostat is bad. If you have never changed the fluid in your vehicle, now would be a good time to do that; otherwise, just replace the thermostat.

 

Throw you Thermostat in a pan of water and put it on stove and heat up. IF the thermostat opens then it is good.

 

Instead of cooking up a pan of fresh Thermostat stew, just go buy a new stat and install it. You're probably going to have to go to the auto parts store anyway just to buy a new gasket.

 

And then Ballbeerfish will use the same water to cook us up some Raman noodles. I hope I get 2 packets in mine!!!!

 

I just changed the thermostat a week ago and it didn't help. Are you saying to change it again?

 

I bet you put the thermostat in the wrong way. Either that, or it's bad. The only other thing I can think of is the damper that control the hot air isn't opening. I would put money on the t-stat.

 

I know I put it in the right way. Maybe I will try another one and see if that helps. Thanks.

 

this is just a stab in the dark but...........the temperature control **** on the dash( thermostat ****) on my truck was just spinning around the post that controls the temp. i thought my heater quit working but i just wasn't switching it to hot without knowing. try this before going to buy anything else that you've already done. i pulled my **** off and the plastic that fits over the post was cracked, a little superglue and i was back in business! good luck!