I have a 2003 dodge ram 1500 with a 5.7 motor and this year when I turn on the heat it never gets hot and takes a long time to come up on the gage which when it does it does not go over half it stays where it should be. some times it will throw out a little warm air but never hot any more. I even did the cardboard trick in front and that wouldn't make a difference because the engine does heat up fine just do not throw out much heat. this past summer the air conditioner didn't throw out very cold air either.
what I am thinking is the thermostat is stuck open so it just keeps going through without being able to heat the air. I am stuck and I would appreciate any help you guys could give me.
thanks
hammer

 

Thermostat could be the issue, but if it was stuck in full-open your truck wouldn't warm up much at all, until it idled for a bit.

You might have a broken blend door, or your Heater Core is clogged...

Since your A/C isn't blowing cold (and assuming you tried recharging it already) I would bet that the blend door is the culprit...

 

if it is the blend door where would that be located, under the hood or under the dash

 

by the way I did try to recharge it last summer but did not help

 

After the vehicle is warm touch the two coolant line going to the firewall on the passenger side. If both are hot and about the same temperature then its most likely the blend door. If one is hot but the other not so hot then heater core is not flowing well.

 

is this blend door the same thing that they had on vehicles years ago where you could manually open it or close it and is this door under the dash or hood.
thanks for the help

 

It a door under the dash that directs how much air flow through the heater core or AC evaporator.

 

thanks a lot and I will let you know what I find out.
thanks again
hammer

 

after running the truck about 5 miles while it was up to temp I checked the hoses that go to the firewall and both where same temp {hot}. so now I will have to try and find that door. would that be near the floor or way up into the dash. also could it be a fuse for the temp dial that goes from red to blue because that must run off electric current.
I guess I will have to get it into a garage to see what I can do.
thanks again
hammer
P.S. sorry about all the questions but you guys helped me with my Durango a couple years ago and your great

 

you won't be able to fix the HVAC **** control... that is a sealed up unit that we don't have electrical prints for... you're best bet is to check and see if you can get a new set of HVAC controls and swap them in there...

It might be that simple but it's hard to say for sure over the internet...