2011 XC70, No Trailer brake lights with Hatch Closed

Post by **rollin_home** » 18 Jun 2021, 07:22

Hi MVS

On my 2011 xc70, I recently installed a hitch with Hopkins trailer light controller HM11143735 “simple plug in , 4 pin connector “. Followed the instructions with no wire splicing, just disconnected plug to lower brake lights through access hole and plug in the Hopkins controller wires.

All appeared fine but on final test it is discovered that the Hopkins trailer light controller is designed to plug into the lower set of brake lights that are only active when the tailgate is open. When the tailgate is closed and vehicle is being driven , this lower set of lights is in-activated and the upper brake lights in the tailgate are activated but the Hopkins brake light controller isn’t aware of this automatic change. Result is no brake lights on trailer while hatch is closed.

Admittedly, access to the proper , upper brake lights appears not easy for a plug in connector. I’m not sure what the solution is.

Any ideas or suggestions? I hate to start splicing into wires.

Thanks

Post by **rollin_home** » 03 Jul 2021, 04:49

Follow up:
I called Hopkins technical support and they were very helpful, they had a new controller made up with a set of plugs that access the tailgate brake lights. Hopkins overnight shipped it to me with a prepaid label to return the other unit. It wasn’t necessary to open the tailgate to install this controller, all connections besides 12v & ground were plugged connections.

My trailer lights all work now and no need to get the Volvo OEM parts and visit dealer for software download. Cost $120, time to implement 2 weeks.

Outstanding Questions:
1) why did eTrailer sell me the trailer light controller that is supposed to fit a 2011 xc70 T6?

2) why doesn’t Hopkins stock these controllers that fit this car instead of making it up custom, too many varieties of vehicles?

Post by **abscate** » 03 Jul 2021, 05:14

Is this a common thing to have brake lights shunted based on tailgate position? I’ve never heard of this, it sounds like a quirky Swedish thing.

Post by **rollin_home** » 03 Jul 2021, 11:00

Once they committed to a design with brake lights in the tailgate, the only alternative is a second set of light in anticipation of driving with an extended load hanging out the back and the tailgate open. The only question would be to have both set on always or switch depending on the position of the tailgate, they obviously decided in favor of complexity, maybe to retain bulb life ??