2nd Gen Non-Engine/Transmission Heater wont heat???

[myoldodge]

I just bought a 98 12valve from texas where the heater is not that important. I live in North dakota where the winter is pretty rough. When the motor is at running temp of 180 deg, the heater will not get very hot. Its already cooling off up here to 35 deg at night. Any help or suggestions would really help.



Thanks

Myoldodge

 

[snappy]

We are close, I'm in Manitoba, just sell me your truck. Kidding aside, there might be a blend door problem. Can you get some heat out of the defrost, or floor or side vent positions?

 

[myoldodge]

Hello again. All vent positions are the same. It blows slightly warm air through all vents, floor, panell and defrost. Any ideas???



Thanks

Myoldodge

 

[GAmes]

With the engine at operating temp feel the two heater hoses, or better check with a heat gun. If one is cooler than the other the heater core is plugged. If they are the same try removing the fan aasy on the passenger side and see if the cavity is full of leaves, dog hair, whatever. It is possible to clean the core a little by spraying it with simple green or all purpose windex or the cleaner of you choice. With the water turned low enough it will drain from the HVAC thru the A/C drain hole.



There are probably posts on how to replace the heater core, but the best money you can spend is on a factory service manual. Genos carries them in book and CD.

 

[AHolt]

The first thing I would check is my

thermostat, to make sure it is not

stuck open.

 

[GAmes]

The first thing I would check is my

thermostat, to make sure it is not

stuck open.

He would never see 180 on the gauge if it was stuck open.

 

[JDriscoll]

Souds really obvious, but are you sure there is enough coolant in the system. I have an old beater car that I run back and forth to work and when the heater stops blowing warm air, I know it is time to add some coolant.

 

[JKinney]

Also research heater treater a quick fix if thats the problem

 

[myoldodge]

I have replaced the thermostat with a new one. And coolant level is right where it needs to be. It was 27 deg outside this morning. I covered the front end up with a cold weather bra to raise the temp to 190 deg. The heater still will not blow HOT AIR, just slightly warm. What should I look at next???? Heater core maybe???? If it is where do I go to get another for replacement???

 

[JKinney]

Ok here is the web site Auto replacement part, blend door fix, Heat, AC replacement parts

 

[Demons_Ram]

Check the simple stuff first.
Are you getting a good volume of air flow out of your vents (regardless of temperature)? Not enough air flow = not enough heat.
If not... blower motor problem or possibly debris plugged evaporator core? Easy to check.
If above items check out go with the blend door servo motor and/or the coupler as the others wisely advised.

Check the following post for a visual of the air flow and blend door.
https://www.turbodieselregister.com...scussions/225293-heater-full.html#post2172599

 

[myoldodge]

Air flow is pretty good. How do you check evaporator core??? I will check the blend door servo motor and assembley

 

[HCannon]

How is your vacuum? Got to have that. You could have a hose loose. The only thing that the vacuum pump does in a 98 is change the heater, air cond. and your cruse control. I had the same problem with the air cond. and it was a vacuum hose. A mouse liked the taste of my hose, when I replaced it everything was OK.

 

[Demons_Ram]

Again, if you are getting strong airflow this probably isn't your problem.

However, since you say it's a new to you truck, it's something that needs to be checked down the road anyway.

Most of us have just dropped the blower motor (just a few screws) out and reached up inside the hole and over to the left. You can touch the bottom of the evaporator core. If there's a lot of debris in there you will feel it. The combination of fishing some out by hand and flushing out with water hose on very low pressure (make sure drain hole is open) usually gets rid of some of it.

I currently have mine out because of a evaporator core leak due to oak leaves corroding it open. It's not a job you want to do.


BLEND DOOR
Looking at the position of my blend door servo motor output shaft the flats are toward the left and right side of the truck when the blend door is blocking the heat off from the heater core. You should also be able to see this on yours below the HVAC box. You should be able to see the coupler rotating when you turn the cold/hot knob.