Suzuki Jimny Service Manual page 61

1A-8 HEATER AND VENTILATION
CAUTION:
When the heater unit is disassembled and reassembled,
locking force of the heater case lock may reduce. In such
a case, tighten the heater case with a tapping screw of
M4×L16 (1) as shown in the figure, or air may leak from its
joint section.