So al lthe sudden my s5 gtu won't start. havent really noticed anything to out of ordinary literally started one day and didnt the next. thinking it was flooded i went through that procedure and that didn't work. Then i noticed that the harness that sits on top of the motor had some of the plastic melting off and the ground wire running from the top of the intake manifold/throttle body area to chassis was also melting the plastic off. I checked the grounds and everything looks ok so what on earth can be causing this problem???

 

Sounds like maybe too much current or a connector somewhere came loose. Do you have any of your fuses larger amp's then they are supposed to be?