I installed the 7 Pin trailer wiring harness and there was a solenoid module that sat inside the passenger side cargo area panel. The relay was supposed to activate the 12V wire in the 7 pin connector based on the key position, but when they deleted the cigarette lighter in 2005 or whatever, the solenoid was always on regardless of the key being in the ignition or not.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

Huh so the trailer plug 12v+ is always hot even key off?

_________________
2005 limited, tinted, OME lift, falken wildpeak 245/75-16, Suncoast, Transgo, Chevy fan+clutch, 195° Kap Stat Mod, Derale tranny cooler, Provent, Stage 2 tune, EGRdelete, Cat delete, Group65 batt, V6 airbox, tow brakes, switchblade key, DIY roof rack, DIY Front bumper,
Future; rear bumper, true tracs, tank fuel pump, webasto heater, 5sp manual