Help! Our old van's 1800 Carver was working fine until the off switch on the conrol panel had no effect and you cannot turn the fan off. No matter what the setting the fan runs on. We in desperation removed the control switch and took out the 12v feed terminal. But then the heater does not work without a 12v supply. We thought it was the control panel unit itself that was the problem and changed that but the fan still runs on. This canes the battery if not on a hook up of course. Some say that we need to change the pcb in the heater itself, but we do not want to spend a lot of money on an old van and are looking for a simpler solution. Anyway it looks a pig of a job! Any ideas anyone?