I, when I got my 05 SEEG, bought a male and female headlamp plug from the dealer, I installed the garage door opener wires into the correct pins on the new plugs. I just removed the headlamp, unplugged the headlamp and plugged it into the adapter I had just made, plugged the other into the existing headlamp plug and ran the power wire to the cigarette lighter, which I didn't use, to operate the opener and was done. Blink the headlamps and the door operates. I removed this jumper harness and garage door module from the 05 when I sold it and replugged it into the left headlamp on my new SERG and have been good ever since, easy / peasy.
All was good until last month when I replaced my garage door and opener, I had read on here about the problems so I told salesaman before purchase I would only buy if he would guarantee my Denali, company car both having Homelink and the bike work before they left after install and if they could not make any of them work they would reinstall my existing door and opener and I would not pay them a dime. He wrote same on order and signed it. It would not work when they started to program, they called Chamberlin, worked all day until after dark from 7:30 am start and finally said it just will not work, i would not let them leave and demanded they reinstall my door opener, They changed opener to a 3/4 hp carriage house opener, knocked off a hundred and left around 9PM. Bike operated opener works great and so does cars, Door literally flies up and down. Works great. Company owner called, about half pissed next day and said he realized they had been "played" during discussion with salesman and the didn't appreciate it, I gave him a fu and hung up. Called better business bureau and yesterday got a apology letter from company and a call from him saying he was sorry would I please update feedback to BBB.