Section IV MATCHING TOWING VEHICLE TO TRAILER
also must match. If the towing vehicle has an air-
38-11. Matching Brake and Electrical Systems.
pressure brake system, the trailer must also have an air-
Matching a towing vehicle and a trailer means more than
pressure brake system. Like-wise, if the towing vehicle
coupling them. The brake and electrical systems must
has a vacuum-type or an electric braking system, the
match. Furthermore, the trailer load must not exceed the
trailer must have a matching braking system.
performance of the towing vehicle.
38-14. Matching Load and Performance. To avoid
38-12. Matching Electrical Systems.
overloading the towing vehicle, excessive loads must not
vehicle and trailer electrical systems must be of the
be hitched to it. The trailer load must not be above that
same voltage. If the towing vehicle has a 6-volt system,
which the towing vehicle was designed to pull. The
the trailer must have a 6-volt system. Likewise, if one
technical manual of the towing vehicle usually has the
has a 12-volt system, the other must have a 12-volt
maximum trailer load listed in the tabulated data section.
system. Connecting 6-volt lights into a 12-volt system
If it does not, the drawbar pull can be calculated as
will cause them to burn out as soon as they are turned
explained in paragraph 29-15c.
on. On the other hand, 12-volt lights connected to a 6-
volt source will give little or no light.
38-13. Matching Brake Systems. The brake systems