TM 9-2320-361-20 14-34. PRIMARY HEATER AUXILIARY DUCT REPLACEMENT This task covers: a. Removal b. Installation INITIAL SETUP: APPLICABLE MODELS M109A3 and M185A3 REFERENCES (TM) TM 9-2320-361-10 TM 9-2320-361-20P EQUIPMENT CONDITION Parking brake set (TM 9-2320-361-10). Auxiliary duct is normally secondary heater installation. NOTE located on van front wall prior to 1. Unbuckle three straps (2) and remove auxiliary duct (1) from van ceiling (4). 2. Remove three screws (3) and straps (2) from van ceiling (4). b. Installation 1. Install three straps (2) on van ceiling (4) with three screws (3). 2. Install auxiliary duct (1) on van ceiling (4) with three straps (2). 14-54