Hey! I'm new at this so take that into consideration!
I have a heating problem with my 1997 F350 crewcab. I have replaced the thermostat and tried everything I know to do (check for leaks, hoses, etc) but still no heat in cab. Any suggestions or help will be greatly appreciated. It is too cold here in the mountains to drive without heat!
Thanks

 

I am not really familiar with the '97 but chances are there is a vacuum problem. Do both heater core hoses get hot (inlet/outlet)? Is there a vacuum controlled valve in line with one of the hoses? If so check for vacuum on the hose going to the valve. Also check for a cracked or broken vacuum line.