Defroster

driving down the road with a/c blowing cold air,all is good.radio playing loud,all good.than thr defroster comes on hot,hot,and the radio will not change station nor adjusting of the volumn of sound.some time latter it does come back to good,but you must turn car off.help…

Year, make, model, etc please?

All vehicles are not the same.

98,ford,taurus