i have a 98 1500 and yesterday afternoon when i started my truck, after driving all day, the heat wouldn't work and it would just blow cold air. Im in southeast PA and we've been getting hammered with snow and its dead of winter so i need heat! PLEASE HELP GUYS IT WOULD BE MUCH APPRECIATED!

 

I bet your thermostat is bad.

 

Could also be heater core. My heat went out and just replaced the heater core and it works fine now.

 

Could be therm. like VW said, did you notice if the temp gauge was in the same spot as usual? Do have any other issues now or prior to this, like CC, vents acting strange, 4x4 working or not, water gurgling sound from the dash?

 

Could be the thermostat stuck open, blend door stuck, plugged heater core.

 

Guys this is really really embarrassing but, i went to check my coolant and it was bone dry. So naturally i filled it up and presto, we got heat. Damn thats real embarrassing..

 

Need to find out where your coolant is going.

 

I wouldn't call that embarrassing, I would call it lucky. Now hopefully it's leaking out of an easy spot like a hose or something.

 

hey i noticed you said something about gurgling under the dash. what could that mean again?

 

gurgling under/in the dash is usually a sign that you have an air pocket in the heater core. Burping the cooling system while the right front end is higher than the left. If you still hear the gurgle a good romp on the gas may help move enough coolant to push the air pocket out of the core...did on mine.