Installed prostart ct3471-tw in 2010 dodge charger, auto, key start, with EVO-CHRT4, power and ground both units through d2d/t-harness. Ground with 1.67k resistor for parking lamps. Using Fortin protocol on bypass and remote start. door locks and trunk release work well. programmed bypass and prostart as usual, tach through bypass. tach programmed good. Modify T- harness as per diagram A- cut yellow wire in T between connectors, connect D1 ylw grn to cut yellow wire,Vehicle remote starts normally most of time, occasionally when cranking with remote starter it will crank longer before actually starting and while cranking starter is cutting in and out, making awful noise.seems worse the longer it sits between remote starts, cannot dupicate with key starting vehicle. Tried reprogramming tach, with no noticeable change. Would using power and ground for remote start from d2d wires as per wiring diagram A on THAR-CHR4 instructions be insufficient. Do I need to hardwire tach signal. Any ideas.