The fuse for the heater blower motor on a 1990 Mercedes 420 SEL is located in the fuse box in the trunk. The fuse box is located on the left side of the trunk, behind the carpeting.
Fuse Number
The fuse for the heater blower motor is number 10.
Fuse Amperage
The fuse for the heater blower motor is a 30 amp fuse.