Difference Between Hopkins 37185 and 47185 4-Pole to 7-Way Trailer Connector Adapters

Question:

I am converting my 4-pin to 7 pin on my 2005 F-150 Crew Cab. Will part#47185 work or should I stick with part #37185? Thanks

asked by: John B

Expert Reply:

The part we offer as # 37185 is actually sold by Hopkins as part # 47185 so it's the same exact part. Your truck is prewired for a brake controller installation, but the wiring isn't ran all the way to the bumper. The wiring stops on the driver's side frame rail.

Follow your 4 pole connector to where it plugs into the body harness on the frame rail. The harness feeding that connector from the front of the vehicle will have an orange wire that carries 12-v for trailer accessories and the blue wire for the brake controller output. The blue wire in that harness would connect with the blue wire on the # 37185 adapter, and the black adapter wire connects to the orange wire in the body harness. I'll link to a help article that explains this further.

I've also linked to a video showing a typical installation, which you might find helpful.

expert reply by: Mike L

Brian

5/24/2024

Hi Mike - 1996 ford f350 reg cab dually 7.5l gas w/ Factory tow package and 4 pin tow connector. 4 pin works great. Found the yellow 12v you refer to on the driver frame rail at the rear of truck but it has no power. The 30A fuse in slot 18 is good. Anything else I should check? Or do you have any articles you'd suggest? Also, where to hook 7 pin into truck if factory blue isnt powered? Thanks!

Mike L.

5/29/2024

@Brian Let's start with the 12V feed wire. The yellow wire carries the left turn signal, not the 12V. It's the orange wire you're wanting. The blue wire won't show any power unless there's a brake controller installed. If it's a proportional controller, it won't have power unless the vehicle is in motion but you can test it by using the manual brake switch/slider on the brake controller. If it's a time-delayed controller, it'll show power with both the brake pedal and the manual brake switch. Let me know if you have any further questions!