TERION UM20-100111B, Installation Manual, Page: 37 / 78

7 Power Connections
7.1 Connection Considerations
There are several considerations regarding how the power cord is connected to the tractor’s
power source. Early and late model tractors have different styles of fuse panels.
The power panels on late model tractors have fuses bussed according to the kinds of circuits,
and use ATO type of fuses. The power connection coming into the bus is connected through
a stud. Typically, there are accessory, ignition, battery, and other busses, each with their own
stud. Use a meter to identify the ignition (switched by key), and the continuously (non-
switched) hot busses. Fuse slots have a hot side, where the power comes from, and a cold
side, where the power goes. This way, the power passes through the fuse on its way to the
device. Some panels do not have a fuse in every slot. Use a meter to identify the hot and
cold sides of the fuse slots.
Attach fused links to the switched and non-switched hot leads. If possible, attach ring
terminals to ends of the fused links. Carefully remove the stud nuts and attach the ring
terminals to the studs. An alternate method is to attach male spade connectors to the end of
the power cord and plug the spade connectors into the hot side of open fuse slots.
WARNING! THE CONTINUOUSLY HOT BUS STUD WILL SHORT
CIRCUIT IF YOU TOUCH THE HOT STUD AND A GROUND POINT AT
THE SAME TIME WITH YOUR WRENCH. AVOID TOUCHING ANY
OTHER METAL POINTS WITH YOUR WRENCH WHILE WORKING ON
A HOT STUD.
CAUTION! Use extreme care when removing the stud nuts. If you drop the nut, it
may be very difficult to recover it.
Some late model tractors with deluxe sleeper berths have secondary power panels located
near the sleeper berths. These panels have switched and non-switched fuse busses. If there
is a secondary power panel, the run from the ITU to the power source may be shorter;
however, care must still be taken to find low resistance ground points.
Power connections on early model tractors are easier as you can simply crimp ring terminals
on the power cables and attach them to the terminal block.
7-1
Mobile Messaging System Installation Manual June 15, 2001
UM20-100111B Terion, Inc.