American MGB Association Message Board

Technical Area => Electrical Items => Topic started by: december2009 on November 30, 2009, 05:37:44 PM

Title: Tach problem
Post by: december2009 on November 30, 2009, 05:37:44 PM: My Smiths tach on my '66 MGB indicates too high, and it gets higher when it has run for awhile. I don't see anything on this in the two tech manuals I have. Any suggestions? - Don
Title: Re: Tach problem
Post by: Art on December 11, 2009, 02:40:04 PM: Hey Don,

This sounds like an internal resistor problem with the electronic Tach, but I would suggest trying a different external tach to verify.

The old tune-up multi-meter units that had a tach and dwell meter for the points should do it or hooking-up a Sun or RAC aftermarket external tach, which can often be found cheap at flea markets, swap meets and garage sales

Replacing the tach or brining it to an electronics shop to test components and repair might be the solution.

I hope that helps. Good luck.

Art