Where is the blower fusible link situated? Blower flips between setting 2 and 4 on 1994 Mercedes-Benz C280

The climate setting (digital is good) The volume doesn't change between setting 3 and 4 and it clicks off and on!
I sense it could be the fusible link or fan resistor.

1 answer 3 comments
most likely blower motor resistor as that controls fan speed
Is it best to replace the resistor or can you clean the connections?
Thanks,
James
REPL ITS MOST LIKELY THE CIRCUIT BOARD INSIDE
Thanks very much for your assistance.
I shall do as you recommend and let you know the outcome.
Much appreciated,
James