[MikeRJ]

My speedometer has never worked since I've owned the car(75 911s)and it's finally driven me crazy, I have to fix it. I pulled the speedometer out of the dash and unhooked the trip cable reset and the other cable. I keep reading about tha ERG box that is on a 75 but I don't see one on mine. Is mine electric? Is the cable that goes into it just for the odometer? I did manage to trace the cable back to the tranny and found two bends in the cable (obviously it's broke), but I Didn't see an ERG box. How do tell if the speedometer is electric or mechanical? I've seen two magazines that have electric speedos for 75-89 150 mph and I've also seen cables for the speedos 75-77 w/ERG box.
Thanks