Table 1. Cab Electrical Troubleshooting Procedures.
TEST OR INSPECTION
N OT E
1. Dome Light Does not
Always inspect the harness connectorsthat are involved in the circuit.
Poor connections can often be the cause of a problem in an electrical
circuit. Verify that all connections in the circuit are clean and secure,
and that all connections are in good condition. If a problem with a con-
nection is found, correct the problem and verify that this diagnostic code
is Active before performing this procedure.
Perform open or short circuit test ateach harness connection to identify
correct harness to replace.
Perform this test only if condition is active.
Test Step 1. Check for Bad Bulb.
1. Remove lens cover and bulb from
dome light (WP 0277) (TM 5-
2. Turn battery disconnect switch to
the ON position (TM 5-3805-293-
3. Turn dome light switch to on (TM
Voltage Between 18 and 26 Volts -
voltage between dome light bulb
Replace dome light bulb and install
center contact and housing (WP
lens cover (WP 0277).
0009, Figure 404). Voltage should
Proceed to step 5.
be 18 to 26 volts.
Voltage Less Than 18 Volts - Pro-
ceed to Test Step 2.
5. Turn dome light switch on and
Dome Light Does Not Operate -
verify dome light operates (TM 5-
Repeat troubleshooting from the
Dome Light Operates - Trouble-
Test Step 2. Check for Open In
1. Turn battery disconnect switch to
the OFF position (TM 5-3805-
2. Disconnect the cab upper wiring
harness connector R-C36 (WP
0009, Figure 282) from dome light
(WP 0009, Figure 283).