1998 dodge ram 1500 wagon with clicking noise?
1998 dodge ram 1500 wagon has a loud clicking noise when you put it into defrost mode what could it be i think it my be the a/c turn off and on?
Answer
The heating system switches between modes by using a vacuum line to open and close ducts.
when a vacuum line has small leaks, it doesnt switch modes smoothly, and usually makes a loud "wack" when it does switch.