How to Wire 4 Pole to 7 Pole Adapter Part # 37185 to Charge Trailer Battery from Vehicle Electric

Question:

I have a 1999, Chevrolet, Suburban S2500. Will I need to do anything extra so my alternator charges my trailer batteries while Im driving? The installation would be from scratch. Can you make any suggestions on exactly what items I will need? Your help will be very much appreciated.

asked by: Jim R

Expert Reply:

Other than properly installing part # 37185, you will not need to do anything special. The 4 pole connector plugs into your existing 4 pole and the other wires will be connected as follows: White grounded to frame, Blue is wired to brake controller output if applicable, black is the a12V power source. The purple wire can be wired as a reverse light wire, reverse lockout for hydraulic brakes, an additional 12V source, or if not needed can be left unconnected.

The black wire is typically connected to the car battery via a 40 amp circuit breaker like part # 9510 so it gets whatever current the alternator is producing.

Keep in mind that the 12V accessory circuit from the 7-way can keep a maintenance charge flowing to the battery, but will not provide enough power to charge a depleted battery. If your trailer battery becomes discharged, you will need to use a charger like part # CTEK56353 and shore power to charge the battery.

expert reply by: Patrick B