just put in a new autometer 5" tach with shift light. the problem is that it is 500rpm lower than the tach in the dash. i think it's wired right, but correct me if wrong. i spliced the green wire from the tach into a thin white wire with a black stripe coming from a black harness in the ecu. is this not the right wire? could something else cause this? could the tach in the dash be wrong? please help. thanks. car is 98 svt.
