my friend has a problem with his car overheating, he turns on the defroster and the heater but it doesnt cool down, what could the problem be

 

Start with a flush and fill of the cooling system, check/change: the thermostat, waterpump, belts, radiator cap and hoses. Look inside the radiator and check for corrosion/build up/plugging, clean the radiator and ac cores externally and make sure the under tray is installed.

 

well did the hoses and the thermostat and the flush, havent done belts or pump yet, he just told me that its still getting hot, shouldnt it the gauge go down when u put on the defrost and heater

 

Not always, it can help but is not a solution or backup.

 

bump