I have installed a Hitachi mini starter on a ZZ4 350 and after 2 1/2 years I was finally able to start the car. Problem is it keeps on starting (with the yellow wire connected)... OK, I found the error, after disconecting the yellow wire and hooking up the purple wire the car does not turn over. I read about a netural saftey switch. Could this be my problem, and do I have to have this switch in order to start.