Trying to install my new solid state tach and things are not going too well. Red wire goes to keyed voltage from the fuse block. Black jumper goes direct to - battery post. Green has gone to the - coil, + coil and the gray/black lead from the MP orange box. Every time i get 2000rpms with the key on and the tach reads backwards when the motor is running. Any ideas? I read one post about switching the polarity by flipping the leads out of the distributor and no luck.

MP orange box and distributor. Solid state voltage regulator, stock ballast resistor, coil.