[MikeInOH]

I would suggest laying under the dash and check the electrical spade connectors especially on the ignition switch but also gauges etc. I chased a number of ghosts in my superformance when I first got it (car was 15yrs old) and it turned out to be some simple loose connections. I ended up slightly crimping each spade and putting a dab of dielectric grease on all of em and havent had a single issue since. These cars have a ton of vibration so tight connections are key. Its an easy thing to rule out....good luck