schamran

I am probably not the first person to post about lack of heat in the cold weather, but I have a 2-3 year old heater core, there is no crud in the suitcase, I just flushed the entire cooling system, The fan works good, but it seems like it doesn't get hot enough. I remember when the heater would drive you out of the cab. I also put a new thermostat in, and I have a fully enclosed winter front covering the grill. What am I missing?

bigredbrick

Thermostat stuck open not allowing engine to build up enough heat? Coolant valve to heater core stuck closed or only partially open? Haven't had problems with mine, but similar system to an old Scout which i used to own.

RuralCruiser007

Did you take the cooling fan off yet?

I do it for the winter, unless I am towing.

Who's stat did you use? Cummins/Dodge I hope. But I have also heard that there are dud stats from them also.

lovin1stgens

im having alot of problems with my heat too. i hear it every time my girlfriend gets in my truck. lol i would rather not have to go out and buy a freakin fifty dollar thermostat if i could help it. i briefly thought of gettin one of those aftermarket heaters u plug into the ciggarette lighter, but those tend to suck alot of juice.

TrkEnvy

Same problem going on in my 91. The needle barely moves off of the C. I dont have a grill blanket but its been in the upper 50s here so i shouldnt need one. I think its my T-Stat stuck open. I need to find one but they are pricey. Never seen a t-stat cost more than a waterpump.

Jim Lane

You shouldn't need a cold front; if the thermostat is working properly the engine should reach normal operating temperature within a reasonable amount of time and stay there as long as you are loading the engine, you might not have a nice toasty hot heater but the engine should be within operating temperature.

I would replace the thermostat, if you cannot afford a genuine Cummins a good Stant will work. I have been running a Stant for many years and I have not had any issues bad enough to warrant me to pay for a Cummins brand, but here in Southern California where it might get down to 50* in the winter I don’t worry about it, I would be more concerned with the hot weather.

Which ever thermostat you install make sure it is installed correctly or even the best will fail.

https://www.dieseltruckresource.com/...6&postcount=10

A diesel engine does not produce much heat without a load.
Jim

Boatnik

It could be the damper not opening far enough to shut off the cold.

TrkEnvy

Where is the damper located on these trucks?? How do I check if its opening or its closed?

lovin1stgens

if u dont wanna go buy a grill blanket, or make a fancy one out of diamond plate or whatever your heart desires, you can always just slip a piece of cardboard in front of the radiator. does about the same thing, and that shiny pretty dodge grill is still displayed and you dont have to take the time, effort, or money to have a grill cover

BCRick

I know when I first got my truck the heater and defroster were really lame and I found that the heater control plate had broken off the tab that secures the cable and allowed the lever to operate but it wasn't moving the damper door. I replaced the control plate and all was fixed. The PO had been running this for years and just thought the heater didn't work very well.

Mick-e

I just cleaned out my trap, and oh **** it was full of crud, and I was expecting all this warm air to come blasting out. wrong

So where do we find this heater control plate?

BCRick

You have to pull the dash apart where the heater control levers are. These levers are connected to a flat plastic plate and if people push hard on the control lever they can break the back tab off the plate which anchors the cable and it won't open and close the plate in the heater box. If you can get to the top of the heater box behind the glove box you should be able to see or feel if the lever is moving when you move the control.

lovin1stgens

is it a pain to get the dash out?

BCRick

https://www.dieseltruckresource.com/....html?t=209884
Click on the above link and the fourth picture in the series shows you the heater control plate I'm talking about. check the back corner where the cable is attached. If it is broken that's your problem. Once again, if you can see or feel the cables move on the heater air box when you move the levers you can also tell if they are working. Then you wouldn't have to take the dash apart.

schamran

I have replaced the t-stat, and it is getting to operating temp. without a problem. Are you guys talking about the (is it called a servo) by the firewall that runs to the heater core? That opens and closes, but I might have to take a closer look at it to see how much. Any other ideas?