Jeep Grand Cherokee 2011-2012 Trailer Wiring Harness 7 Pin Aug 29, 2016This is the factory OEM genuine Mopar trailer tow harness that you need for a seven pin towing hook-up. It has everything you need to make your 2011-2012 Jeep Grand Cherokee look like you didn't forget to opt for that trailer tow package. Easy to follow "how to" instructions are included so you don't need to be an electrician to hook this one up.5/5(1) 2012 Jeep Grand Cherokee OE Wiring Harnesses & Stereo Jeep Grand Cherokee 2012, Aftermarket Radio Wiring Harness by Metra®, with OEM Plug. For aftermarket stereo. Metra preassembled wiring harnesses can make your car stereo installation seamless, or at least a lot simpler.