climate control issue

[wolfie1978]

Desperatly need some help with my 2007 r class climate control. I've only recently bought this car and it appears the climate hasn't been serviced for a while. Last week during the rain the climate fan cut out. Turned out where the air comes in for the climate the water drain off hole was blocked and the pollen filter was wet. I've cleared the drain and replaced the filters but now the front interior fan starts running about 5 seconds after the engine is shut off. Any ideas why it's doing that and how to fix it?