Pressure Switch and Air Hoses Replacement (Fig. 6-19).
Replacement procedures are the same for pressure switch
and air hoses on left and right sides.
(a) Open top deck grille doors to expose turbosupercharger and pressure switch
(b) Disconnect high and low air pressure hoses from pressure switch and from
turbosupercharger compressor housing filter. Remove hoses.
(c) Remove screw and lockwasher securing pressure switch mounting bracket to
turbosupercharger mounting support. Remove pressure switch and mounting
(d) Remove screw and lock-washer securing harness assembly ground lead to
pressure switch mounting bracket.
(e) Disconnect harness assembly connector from pressure switch (view B).
(f) Remove adapters and packings from inlet and outlet (HIGH and LOW) ports of
pressure switch. Discard packings.
(g) Remove two remaining screws and lock washers securing pressure switch to
mounting bracket. Separate pressure switch from mounting bracket.
(a) Put replacement pressure switch on mounting bracket and secure with two
bottom screws and lock washers (Top screw and lock washer will be put in
when ground lead is installed later).
(b) Install adapters and new packings in inlet and outlet (HIGH and LOW) ports of
replacement pressure switch.
(c) Connect harness assembly connector to electrical connector on pressure
(d) Install harness assembly ground lead on pressure switch mounting bracket
with screw and lockwasher.
(e) P o s i t i o n a s s e m b l e d p r e s s u r e s w i t c h a n d m o u n t i n g b r a c k e t o n t u r b o -
supercharger mounting support and secure with screw and lockwasher.
Long air pressure hoses go on engine right bank pressure
switch, s h o r t air pressure hoses go on engine left bank
(f) I n s t a l l a i r p r e s s u r e h o s e s o n a d a p t e r s i n p r e s s u r e s w i t c h a n d t u r b o -
supercharger compressor filter housing.
(g) Perform dust detector operational test (para. 6-17j).
(h) Close top deck grille doors.
Engine Wiring Harness Replacement (Fig. 6-20).
( 1 ) Removal
(a) Disconnect three battery ground cable assemblies from battery terminals.
(b) Remove top deck transmission shroud and engine shroud (TM 20-1).
(c) Remove screw and lockwasher securing wiring harness ground lead to right
and left bank pressure switch mounting brackets (view A). Disconnect ground