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Posted by: don_newton_alpha Aug 6 2011, 08:46 AM

So i am driving home the other day on the highway and i notice that my tach is bouncing up and down. Then after a while it settles down but instead of being at 3k rpm its at 2k rpm. I was wondering if any one knew what was going on or am i going to have to search through all the connections for the tach. Thanks for the help

Posted by: Spoke Aug 6 2011, 09:35 AM

The simplest thing to try is to remove and re-insert all electrical connections on the tach and at the coil.

Is the bouncing happening at certain RPMs?

The tach bouncing could also be a sign of points wear.

Posted by: StratPlayer Aug 6 2011, 09:51 AM

Points or condenser going bad will cause the tach to bounce.....

Posted by: markb Aug 6 2011, 10:57 AM

QUOTE(StratPlayer @ Aug 6 2011, 08:51 AM)

Posted by: vsg914 Aug 6 2011, 11:20 AM

Points or condensor going bad won't cause the tach to bounce. If they are "going bad" they cause the engine to miss. The tach is just reacting to what the engine does. More than likely, you have a loose connection at the tach, as Spoke suggested (black wire with purple stripe), or a blown fuse.

Posted by: einic Aug 6 2011, 12:56 PM

Points or condenser going bad will cause the tach to bounce!!

Posted by: don_newton_alpha Aug 6 2011, 01:58 PM

Ill check the connections later today but i have a relatively new electronic ignition so i dont think that that is the problem. Will let you know what i find

Posted by: benalishhero Aug 6 2011, 04:46 PM

My tach was bouncing two days ago. I ended up losing my alt Friday. New alt no more bouncing tach. My dash lights are the brightest they have been since I have owned the car now.