Dodge: no heat!!, temp guage, saskatchewan canada

Question
we have a 1998 dodge ram 1/2 ton, 4x4, 318, and even after letting run for 1/2 hour temp gauge has still not reached operating temp.  It also blows no heat.  we have changed the thermostat already as well as put cardboard between front end and rad and still NOOOO heat.  Any suggestions.  we do live in Saskatchewan, canada and it has be 30 below zero for a week or two, but since winter hit altogether it does not want to warm up.  Could the temp gauge just be stuck?  Any suggestions...please help.  we have a 2004 jeep liberty and it heats up fine and some friends of ours have a 2004 dodge dakota and also have no problems. Thanx alot. :)

Answer
Marnie,
Have you tried back flushing the heater core?Let me check a little further on this,i'll respond in a little while with the latest results.Also when the truck reaches temperature,put your hands on the hoses running to the heater core and check to see if they are getting hot.If the hoses are hot,you will need to back flush the heater core.It is possible for a temp guage to be messed up but you still should be getting heat from the vents.When you say blows no heat do you mean the blower motor is not working or it's just not blowing hot air?If the temp guage is messed up you will know for sure when you check the hoses running to the heater core.If you've ever noticed in a radiator when you remove the cap sometimes you'll have a white looking crust type build up in the radiator,well the coolant flows through the core just as it does through the radiator and can sometimes build up just as a radiator does.Let me know what you come up with!Thanks RamMan