TM 5-3805-291-23-1
TROUBLESHOOTING WITHOUT A DIAGNOSTIC CODE - CONTINUED
0008 00
Table 2. Electrical System Troubleshooting - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
4. Check power to relay coil.
1. If battery voltage is present, go to Test
20. Horn/Dome Light(s) is
(a) Horn relay remains removed.
6.
Inoperative - Continued.
(b) Battery disconnect and engine
2. If battery voltage is not present, go to
start switches remain in ON
Test 5.
position (TM 5-3805-291-10).
(c) Select service drive mode on main
light switch (TM 5-3805-291-10).
(d) Measure voltage at horn relay
between wiring harness pin 85,
wire A652 (BU), and ground.
5. Check main light switch output circuit. 1. If continuity is present, replace main
(a) Turn battery disconnect and
light switch (WP 0061 00).
engine start switches to OFF
2. If continuity is not present, there is an
position (TM 5-3805-291-10).
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 0195 00 thru WP 0201
wiring harness (WP 0061 00).
00).
(d) Check continuity at main light
switch between wiring harness pin
J, wire A652 (BU) and horn relay
wiring harness pin 85, wire A652
(BU).
6. Check horn relay coil ground circuit. 1. If continuity is present, there is an open
(a) Turn engine start switch to OFF
circuit between horn relay and horn.
position (TM 5-3805-291-10).
Replace wiring harness in question
(b) Battery disconnect switch remains
(WP 0195 00 thru WP 0201 00).
in ON position (TM 5-3805-291- 2. If continuity is not present, there is an
10).
open horn relay ground circuit. Replace
(c) Horn relay remains removed.
wiring harness in question (WP 0195
(d) Check continuity at horn relay
00 thru WP 0201 00).
between wiring harness pin 86,
wire 200 (BK), and ground.
7. Check power to horn.
1. If battery voltage is present, go to Test
(a) Disconnect wiring harness from
8.
horn (WP 0095 00).
2. If battery voltage is not present, there
(b) Turn battery disconnect and
is an open circuit between horn and
engine start switches to ON
horn relay. Replace wiring harness in
position (TM 5-3805-291-10).
question (WP 0195 00 thru WP 0201
(c) Select service drive mode on main
00).
light switch (TM 5-3805-291-10).
(d) Measure voltage at horn between
wiring harness pin 1, wire 331
(OR), and ground.
0008 00-66
