no heat on 2002 Dodge Ram 1500

i turn on the knob for the heat and i get it only for a few seconds the it goes cold. why aint i getting heat, and what can i do to fix it

Asked by for the 2002 Dodge Ram 1500
Getting it for only a few seconds seems like a possible engine temperature issue. In other words, it's not hot enough and cools down even more with your fan on.

Have your engine thermostat checked as it may be sticking open.