Hi my 02 cummins has no heat however the engine is very good with temps, it warms up in less than 10 min to 190* but i have no heat at all until about 180* and thats if the blower is on 1 and it comes out warm not hot, if i even think about turning the blower up im better or using the a/c... im ordering a new heater core by the end of the week but does anyone else have this problem or the solution? I also made sure the actuatoe for the temp selector was working properly. Any help is appreciated thanks!

 

When's the last time you changed your coolant? If it has been a few years, then you are probably due for it. Because while you are changing the coolant you can flush out the heater core. A few guys here have had good luck doing that.

 

definately sounds like a coolant issue. either your low or have bad coolant.

 

Feel the heater hoses coming from the firewall to see if they're both hot. If they're not then the heater core is plugged but if they are then your hot/cold temperature door under the dash probably isn't working. If you turn the key to ON and change the temperature selector from hot to cold then cold to hot, put your ear down by the passengers floor and you should be able to slightly hear the little electric motor which moves the door.

 

Blend door is cable actuated.

 

Nope..........these trucks have an electric motor on the blend door.

 

I looked in my '01 FSM, and sure enough, looks like a motor. Is that a late 2nd gen setup, as I know its a cable leaving my heater control **** in my '98 24v.

 

Dont know. Not sure when or if they changed anything. But you can definitely hear the little more humming away if the engines not running.