54–01 Ground Cables
Checking and Cleaning
Check that the ground cables are clean, undamaged,
and tight. If needed, disconnect them, clean the mat-
ing surfaces with a soda solution, then connect them
securely. Spray the ground cable connections with
dielectric red enamel. See
for approved part
numbers.
Material
Part Number
Dielectric Grease
48–02349–000
Dielectric Red Enamel
Spray
MMM 1602 IVI Spray-
Sealer (Spray-On B–6–665)
Table 1, Approved Dielectric Grease and Red Enamel
54–02 Electrical Wiring
Checking
Dash and Cowl Area
1.
Uncover the electrical power center located un-
der the dash and remove the fasteners. See
2.
Check that all the relays are firmly seated in their
mounting blocks.
3.
Check the turn-signal flasher. Make sure that the
two male and female connectors are firmly con-
nected. Check that the flasher fuse is firmly
seated in its holder.
4.
Test the electric horn. If it does not work, check
the adjustment screw on the horn unit. Turn the
screw in or out, until the horn works. If the horn
still does not work, check the wiring to it. If the
wiring checks out okay, replace the horn.
5.
Check all the connectors on the right-hand side
of the bulkhead, inboard of the radiator surge
tank. See
. Check the terminals for tight-
ness, signs of damage, corrosion, and presence
of dirt. Repair, replace, or clean the terminals
and connectors, as needed.
Chassis
1.
Check the main wiring harness. Check the wiring
insulation for damage from chafing or heat. Also
check for kinks. Reroute, repair, or replace the
wires as needed.
2.
Disconnect the battery cables from the battery
posts, and check for corrosion.
If corrosion is found, clean the terminals and
posts, using a wire brush and a solution of bak-
ing soda and water. Use the solution sparingly.
08/09/96
f541333
Fig. 1, Under-Dash Electrical Power Center
f541351
2
3
08/23/96
1
4
5
6
7
8
9
1.
Surge Tank
2.
Magnetic Switch
3.
Bulkhead
4.
Power Stud
5.
ABS Connector
6.
Engine Connector
7.
Ground Stud
8.
Electronic Engine
Connector (if installed)
9.
Chassis Connector
Fig. 2, Bulkhead Electrical Connectors
Electrical, Instruments, and Controls
54
School Bus Chassis Maintenance Manual, October 1996
54/1
