My military son left my daughter a 2001 2WD B2300 truck to drive while he's overseas. The heater blows only slightly warm air. Not a good thing with winter approaching here in Colorado. Any thoughts on how to fix would be greatly appreciated.

 

Thermostat stuck open usually. Possible heater core restriction. I would replace the thermostat as 99% of the time that is the cause.

 

Much thanks. I think you're right. Ordered a thermostat last night.