i have bought a peugeot expert van and the heater fan comes on constant when the ignition is turned over(not on the first and second ignition clicks) but only when the engine is turned over. had the heater controls to pieces and the PCB looks ok. i removed the pcb and the fan still kicked in when i turned the engine over. its like its getting a permanent live to the relay when engine is running. checked the relay and it works properly.bit of head scratching going on and a bit baffling to say the least, any one got any idea what the problem may be.

Many thanks Sean.