Have a 1978 Trans Am with 403 engine and rally cluster. Installed a new tach (old one did not work). Car starts fine when the 2 pin connector not attached to the tach (rest of the cluster plugged in), but when i connect the tach i cannot get the car to start. I have changed the PU coil (tested bad), the HEI module, and the ignition coil. Have double/triple checked to ensure installed correctly, and still cannot get car to start with tach connector attached. i have also tested the output from the connector with the car running and the voltage increases as you would expect with the increase in RPM. Suggestions on where to look now?
