TM-9-2320-334-13&P LHST Operator, Field and Parts Manual M1147A1 Trailer Download
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TM 9-2330-334-13&P THEORY OF OPERATION – Continued 0003 00 0003 00-3 Change 1 ELECTRICAL SYSTEM The towing vehicle electrical system supplies all electrical power to the trailer by way of a 24 VDC (12- pin) connector at the rear of the towing vehicle. In order for the towing vehicle to supply electrical power to the trailer lights, the main light switch of the towing vehicle must be on. The master power switch of the towing vehicle must be positioned to ON in order for electrical power to be supplied to the trailer Anti-Lock Brake System (ABS) Electronic Control Unit (ECU). The trailer electrical system is dependent on the towing vehicle electrical system. The towing vehicle electrical system must be operational in order for the trailer electrical system to be operational. The trailer lights and ABS ECU operate on 12 VDC. All power to the trailer lights and ABS ECU is routed from a 24 VDC (12-pin) intervehicular cable to a voltage converter box before allowing power to flow to the lights or ABS ECU.