tach cuts in and out

[84EdH]

1979 century re-powered with 5.7 carbd engne and thunderbolt 4. Ignition.

Engine runs great. Tach works, then stops working. At random. Even on muffs. Wires tight. It did this with old engine also. Is this an internal problem in tach? Tach is original.

 

[gm280]

Re: tach cuts in and out

It is possible for that to be internal. But before you buy a new one, check to see if the positive and negative wires are supplying voltage and not cutting out as well. You stated that you checked to verify the connections are tight, but are they clean and not corroded and what about the other ends of those wires. Have you verified those connections as well. Once you verify ALL connections are both clean (shiny) and tight, then you may need a new tachometer if it still cuts out sporadically...