TM 5-3805-290-23-1
TROUBLESHOOTING WITHOUT A DIAGNOSTIC CODE - CONTINUED
0008 00
Table 2. Electrical System Troubleshooting - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. Check dome light operation (TM 5-
1. If dome light operates correctly, go to
23. Horn is Inoperative.
3805-290-10).
Test 7.
2. If fuse is OK, temporarily replace horn
relay (WP 0054 00). If problem still
exists, reinstall original relay and go to
Test 3.
2. Check horn fuse (TM 5-3805-290-10). 1. If fuse is open, replace it.
2. If fuse is OK, temporarily replace horn
relay (WP 0054 00). If problem still
exists, reinstall original relay and go to
Test 3.
3. Check power to relay.
1. If battery voltage is present, go to Test
(a) Remove horn relay (WP 0054 00).
4.
(b) Turn battery disconnect switch
2. If battery voltage is not present, there
and engine start switch to ON
is an open circuit between horn fuse
position (TM 5-3805-290-10).
and horn relay. Replace wiring harness
(c) Measure voltage at horn relay
in question (WP 0169 00 thru WP 0175
between wiring harness pin 1,
00).
circuit 114 (RD), and ground.
4. Check power to relay coil.
1. If battery voltage is present, go to Test
(a) Horn relay remains removed.
6.
(b) Battery disconnect switch and
2. If battery voltage is not present, go to
engine start switch remain in ON
Test 5.
position (TM 5-3805-290-10).
(c) Select service drive mode on main
light switch (TM 5-3805-290-10).
(d) Measure voltage at horn relay
between wiring harness pin 5,
circuit 8630 (BU), and ground.
5. Check main light switch output circuit. 1. If continuity is present, replace main
(a) Turn battery disconnect switch
light switch (WP 0049 00).
and engine start switch to OFF
2. If continuity is not present, there is an
position (TM 5-3805-290-10).
open circuit between main light switch
(b) Horn relay remains removed.
and horn relay. Replace wiring harness
(c) Disconnect main light switch from
in question (WP 0169 00 thru WP 0175
wiring harness (WP 0049 00).
00).
(d) Check continuity at main light
switch between wiring harness pin
J, circuit 8630 (BU) and horn relay
wiring harness pin 5, circuit 8630
(BU).
