my heater in the car goes hot cold hot cold stays hot for 4 secs cold 4 secs and so on
heater on 2005 Volvo S60
Make sure that your coolant is full to the right level line on the coolant reserve tank. Then, you need to make sure that your car is getting hot enough, feel the upper and lower radiator hoses, they should be too HOT to touch, when your car is warmed up for say, 20 minutes. Any Check Engine Lights on? If so, have the codes checked out.