I am selling an original 1975-77 Chevy Corvette С3 L48 Instrument Tachometer OEM Original 5300 Red Line in very good used condition. I have no way of testing its working condition. If there are any tests, you want me to do with an Ohm meter I can check for you. This was removed many decades ago and has been stored away. I will be listing more Corvette parts over the next week as I find the time. Please ask any questions you may have before purchasing.