Originally Posted by GeritgoulAnd bgrd351, if this does not fix it then I'm def gettin a fluke and give that a try..so far the dealership hasn't impressed me very much...I'm afraid they only know how to hook up a diagnostics cable but can't use a meter
I've used that exact setup for years. But as good as the meter is, I usually use a test light as it is easier to see from inside the vehicle. Otherwise you have to keep getting out of the truck to view the meter or maybe put the screen up against the windshield. But it is a good reason/excuse to buy that nice fluke you have been eyeing. :-)
As for dealers, when I was a mechanic in the 90's I would get cars all the time that they couldn't fix. But you have to remember, all mechanics make $$ by kicking out the most cars...not by working on one car all day. Plus, newer cars are so computer reliant that new mechanics don't know the old "shade tree" tricks.
As for the alternator, it could be the cause as I stated before. I had more than one that the regulator would go to ground like when the car was running thus acting like you had your lights on.