Compatibility of Hopkins 4-Pole to 7-Pole Adapter 37185 with 4-Pole Wiring on 2017 Subaru Outback  

Question:

Expert Reply:

The Hopkins Adapter # 37185 connects to a 4-pole flat type trailer connector on the vehicle, such as # 118467, and allows the three lighting circuits in the 4-pole to be available in the 7-way RV-style connector format. This item is not vehicle-specific and it will work with the standard 4-pole harness on virtually any vehicle. An installation video is linked. You will simply plug in the 4-pole to the mating connector on the adapter and then secure the white ground wire to a clean bare metal surface.

The trailer lighting signals from the connected 4-pole harness - stop, turn and tail lights - will appear on the 7-way pins as noted in the linked photo. Since # 37185 also has a 4-pole connector these lighting signals will also simultaneously appear on the 4-pole pins as well.

The other functions typically carried on a 7-way connector, apart from the stop/turn/tail lighting signals, are 12V auxiliary trailer power, trailer brake power and reverse lights. These additional functions will NOT appear at the 7-way adapter unless you make those additional circuit connections using the included pigtail leads. If the trailer has only basic lighting these leads can simply be taped up out of the way to protect them for future use.

Since you have a 5 x 8 utility trailer odds are that the trailer does not have brakes, nor an on-board battery that needs the 12V charging circuit nor reverse lights. It is not uncommon for a trailer with only lights (and no other wiring functions) to have a 7-way connector simply to make the trailer more compatible with the 7-way type wiring found on most tow-worthy vehicles.

The linked article on trailer wiring illustrates the various types of connectors and the signals they carry from the vehicle to the trailer.

expert reply by: Adam R

0

click to enlarge