TM 10-3930-669-20 7-12.  CAB HEATER BLOWER SWITCH REPLACEMENT. This task covers: a.  Removal b.  Installation INITIAL SETUP Tools and Special Tools Tool Kit, General Mechanic's: Automotive (Item 1, Appendix B) Materials/Parts Tags, Identification ( Item 21, Appendix C) Equipment Condition Engine OFF (TM 10-3930-669-10) Parking brake applied (TM 10-3930-669-10) Wheels chocked (TM 10-3930-669-10) Cab door opened (TM 10-3930-669-10) Batteries disconnected (Para 7-48) a.  Removal (1) Remove four screws (1) and heater temperature control (2) from cab (3). NOTE •    Tag and mark all wires prior to removal. •    Depress center tab on ends of switch to remove switch. (2) Remove switch (4) from cab (3). (3) Disconnect three wires (5) from switch (4). 7-27