jghawkeye

Help!!
I have a 2011 GL 450 with a 5 pin electric adapter for a trailer for my 2010 Malibu ski boat. The trailer has surge brakes and when the car is in reverse the brakes do not disengage as they should . therefore I can not back up trailer. A trailer place has told me I have no power going to that 5th prong which should be attached to the reverse lights i have been told. The dealer has been no help at all. No one has a clue. What do I need to do. Amazed I can not just plug in a and go. Thanks for any help!

Jim

deuce zer0

With a surge brake trailer, the brakes are applied when the trailer hitch is compressed by the tow vehicle braking. To reverse a trailer with surge braking you have to stop the compression. Mine had a little lever that I had to get out and push down when I needed to reverse. Nothing power related.

EWT

The purpose of the fifth pin is to disengage the surge brakes when backing up. I have surge brakes on mine, and with the electrical connector connected, backing up is no problem. If I try to backup without the electrical connection, I don't get far. I'm not sure what the fix is, but I'd guess it is a SAM programming problem.

gbigpapa

Jim,
The pin need to provide power for the reverse lockout solenoid on the trailer is center pin shown in photo.
Are you using a 7-5 adapter that works with the boat when used on another vehicle? Some 7-5 adapters are set up to pull power from the auxilary circuit and not the reverse circuit.
Did the trailer place actually test your vehicle to determine there was no power or did they just suggest no power was present? If they tested it and found no power and the fuses are good the next questions I have was the hitch dealer or factory installed? The factory installed hitches should come with a SAM ready to hitch up the trailer. The dealer installed ones may not. Ask your dealer to verify the rear SAM in the truck to see if it the correct one.

This thread my also help you:
https://mbworld.org/forums/gl-class-...tallation.html