TOMG

When I start my 1982SC The Tachometer will jump to 5000rpm bounce around then go back to normal. Not all the time...Car runs fine! When it acts up I'll put chutch in ...bring revs down and it will be ok.. Whats Happening?Alternator?regulator? bad tach?

Randy V

Looks like you're new here, Tom - and a Sponsor, too. Welcome!

I'll move this from 'Help and Feedback' to the 911 forum - I'm sure someone there can 'help'.


RV

Bill Gregory

I've seen that happen when something in the charging circuit was about to give up the ghost. Recommend testing the alternator output. There are several articles and posts around that discuss how to do that, both here and I believe on the Rennlist tech site at tech.rennlist.com.

Peter Zimmermann

If your alternator is failing it's allowing an overcharge condition ('82/83 SCs have an internal regulator, mounted on the alternator, that can be troublesome). Usually when that happens you also have the smell of rotten eggs in the car, and noticeable acid boil-over at the battery. Trust the moderators and test that baby - before any more driving. You don't want a voltage spike to take out something in your car, like your expensive Alpine, your tach, etc...