Hey check this out I pull up shut off the truck and am yakin on the phone when my speed odemeter needle jumps up to twenty mph floats back down twitches then hangs at one mph. I thougt I should get a preist so I start it up and shut it back down and watch it and it does it again only this time i notice that it jump when the alarm light starts to flash does anyone have a clue as to what this is . and should I go to teh service tech or get a preist to do na exorsiam?