Tach problem
 

I just purchased a 1982 sc and the tach is not working, a few people have suggested that is was a volt problem but there is no variation in the headlight brightness. The tach will work fine then stop, then when you hit a bump it shoots up and starts working like a loose ground or a bad connection. Any help would be great

Pulling the tach out gently and checking all the connections on the rear of it would be the first thing to check. Removal has been discussed on this forum many times so use the search function and know that it is your friend.

I had similar tach. problems, I did the usual trouble shooting (search this forum). After I exhausted all the trouble shooting tips on this forum (do a search) I sent mine in to North Hollywood and had it repaired\rebuilt. Now all is good.

Jerry M
'78 SC