The tach in my 78 has never worked. I was wondering if anyone has ever put an aftermarket tach in place of the factory one? I have looked at some autometer units that look like they might fit. I don't know whats wrong with mine. Was told that they are a problem. Is there anyone particular thing that goes wrong with these units? I am not very good with electrical. I'm just looking to see what kind of advice I can get. Thank you.