Electric brake signal interface unit for 2.5 and 5 ton trucks. This device provides an isolated contact closure when the vehicles brakes are applied. The contact closure is used to activate the electric brake controller for trailer braking action. (The brake controller is supplied by the customer)
P/N 4M-6003. Made in USA. Simple to install. Mounting hardware included.
Plugs into existing vehicle wiring at the brake light switch. Sealed/waterproof, can be mounted at any convenient location near the brake light switch. Vehicle must use the air operated 11602160 brake light switch. If the older hydraulic switch is installed replace it with kit p/n 12255668. Later model trucks with air brakes will have the correct switch.
Connection info (wires are tagged with numbers referenced in bold)
-Chock the vehicles wheels for safety before beginning work on the vehicle.
-Follow wire connections in the order listed.
-Mount device so leads with rubber shell connectors can reach vehicle’s brake light switch.
#7 (ring terminal lead) attach to one of the mounting screws. If wire #7 is not grounded device will not function. Make sure mounting surface is clean and screws are installed tightly.
Turn on main light switch to “stop light” before proceeding. Make sure vehicles batteries are functioning correctly as well. Locate vehicle’s air operated brake light switch. Ensure the normal service brakes are not being applied.
#75 (two rubber shell connector leads) plug one lead into vehicle’s existing brake light switch and other lead into the original wire that was just unplugged from the brake light switch.
Listen for a click at the interface box when brake light switch wires are attached. If you hear a click, return the first switch wire to its original location and use the vehicle’s other brake light switch wire. In other words, you should not hear a click when the brake light switch wires are initially connected to the 4M-6003.
#53 (two unterminated leads) connect to customer supplied electric brake controller and 12 volt power source. These leads provide a contact closure (10 amps max) when the vehicle’s brakes are applied. Generally one lead will go to the 12 volt power source and the other will go to the brake controller’s brake signal input. Follow brake controllers instructions for remaining wiring.