Installation Supplement

for Brake Controller Pigtail for Freightliner Chassis
(built after December 2002)

Part #EC-4128

Date: June 1, 2006 (Revised October, 2007)
Use with Unified Tow Brake Towed Vehicle Kit (TV-1000K and TVH-1000K)









Freightliner Trailer Brake Controller harness


Freightliner rear engine chassis built after December 2002 are pre-wired for supplemental braking. This connector will allow the Unified Tow Brake controller to be plugged into the Trailer Brake Controller connector in the motor home so that the existing wiring can be used instead of running the Unified Tow Brake motor home harness.

Be sure the ignition is off during installation of the Brake Controller Pigtail.

The Freightliner Trailer Brake Controller wiring and connector can generally be found just above the brake pedal under the dash. The harness is marked by a ?flag? type label.








Freightliner harness with tow brake Pigtail connected

Plug the pigtail connector with three wires into the Trailer Brake Controller connector.

Find a switched 12-volt source for the remaining (red) wire that is not inserted into the pigtail connector. Freightliner recommends using their Bodybuilder Connector 1, pin B, which is a pink wire numbered 306B. This is a fused, ignition-switched connection. Splice the red wire from the pigtail into the switched 12-volt source.

Plug the other end of the pigtail into the connector from the Unified Tow Brake controller.

EC-4128 Wire Colors & Function
Color Function
Red Switched 12v
Black Ground
Orange Brake Light Switch
Blue Modulated to Power Module in TV

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