Heater fan

The fan is sounding like something is catching on it I've taken it out as far as it will go and given it a tap by tapping it back in on the housing which seems to work for a bit then it comes back think something is dropping to the bottom of the housing but over time it gets sucked back up .I can seem to find the fresh air intake either to check if anything is getting in that way can anyone tell me were to find it ?
 
Back
Top