I have an diesel 2,5 TDI 1996 when i wil start the ingine after a wile and he is cold the light for the heater? lamp on the dashboard wil lightup but he,s going verry fast on and uot but there is also a noice from verry fast klick klick under the dashboard ,and after the engine is on he still goes klick and after a wile it stops can you tell mee whats wrong?