Your 98 Dodge Ram blows hot air at 40mph and smells like antifreeze for no reason?
heater core is more than likely leaking..
What would be leaking from the cooling system under the dashboard passenger side on a 1999 Dodge Ram Van?
Your Heater Core Sounds Like. heater core Another answer== Water from condensation when using the AC, or coolant from the engine cooling system. Test to tell: if it smells like antifreeze, the heater core is leaking. No smell or just smells wet, it it condensate and a drain line is plugged or blocked causing the water to back up into the passenger compartment.