Okay, I'm tired of making guesses on my car and I'm considering buying an ALDL cable so I can hook my laptop up to it and see whats going on. I know these are probably dumb questions, but how does it work? Do I hook it up before starting the car, or do I wait until it's warmed up and on the highway? I have the WinALDL downloaded but it doesn't explain how to use it.

I can't get my torque converter to lock up and I'd like to see if the computer is even commanding it to do so in the first place. If not I would know something has been changed by the previous owner.