7-Pin Trailing wiring on 2008 CX-9
 

New forum member, first time poster, loving my CX-9!


I have an '08 CX-9 with factory hitch and 4-pin connector. Looking to add a 7-pin adapter for pop-up camper. The adapter connects into the current connector for brakes, running lights, and directionals but I need to add aux power to the 7-pin (I do not need brake assist at this time). I noticed a wiring harness going to a long (~3 to 4 inch by 1/2 inch) plastic piece just behind the factory trailer hitch under the back bumper. Does anyone know what this is and what its purpose is? Does it contain wiring I can use for aux power? If not, what is the best method to run aux power to the 7-pin connector?


Thanks,
John (MA)
2008 CX-9 AWD Touring

Pulled a lot of campers and own my own. What purpose is the aux power going to be used for? Battery charge?

Yes, to charge battery on camper. I am assuming that it should be on aux power to only charge when the vehicle is running. Am I correct with that thinking?

If I'm correct, and I don't claim to be all the time, the smaller pop up trailers didn't work that way. There is a charge mode for the battery when hooked to shore power, but that was it. Unless this is a newer unit that has that option.

The need for a good/charged battery when towing was to operate the brakes in the misfortunate event of a break away and the trailer needs to have that option. Does the trailer have a 7 pin connector? If so, I'd stop a the local RV store to see if they can shed some light on pin use. I've found in the past that RV's are the worst for getting manuals and accurate info. I can't think of any circuit in the back of the car I would want to tap into for that.

If you do end up wiring an aux circuit for the trailer, you would have to get all creative. battery to fuse, to switch so you can turn power on and off. CX-9 has a battery saver system that cuts power off to accessories 2 mins. after key off, incl. headlights. Kind of amusing at times because people think they have auto headlights when they are actually driving with headlights all the time. doesn't hurt anything, just shortens bulb replacement intervals. From the switch, to the 7 pin.

But you still have to verify which pin for the battery. Vehicle disconnected, you would have 12 volts on trailer pin.

Thanks Sparky, but you have gotten way off topic. Of course the trailer has a 7-pin connector or I wouldn't be asking this question. Yes, of course there is a need to charge the battery on the trailer for lights and other electric needs like the mini fridge. Now with all that out of the way I would like to repost my original question...

I have an '08 CX-9 with factory hitch and 4-pin connector. Looking to add a 7-pin adapter for pop-up camper. The adapter connects into the current connector for brakes, running lights, and directionals but I need to add aux power to the 7-pin (I do not need brake assist at this time). I noticed a wiring harness going to a long (~3 to 4 inch by 1/2 inch) plastic piece just behind the factory trailer hitch under the back bumper. Does anyone know what this is and what its purpose is? Does it contain wiring I can use for aux power? If not, what is the best method to run aux power to the 7-pin connector?

I apologize, my brain gets to rambling and I forget to take my hands off the keyboard. I also forget pop ups have come a long way since I used one. I'll take a look at my daughters tomorrow and see if I can see that piece your referring to.

Follow up: Learned from other sources that the 12V hot lead should be connected via a 10 gauge wire directly back to the battery with a 40 fuse in line. Just in case others are interested.

That's along the line I was thinking, just got to elaborate with my anal way of doing things. That piece of plastic you were referring to is one of the antenna for the keyless