Tach stopped working-??

[GetX'd]

I have a 68 GTX with a factory tach as part of the instrument cluster. All the other instruments work fine but for some reason the tach just stopped working. It has always worked fine. Then a couple of months ago it got fickle and you had to tap on the plastic panel over it and it would start working again. Then it just stopped working period. When it worked it was accurate. I'm a little stumped - anyone have any idea what could cause what I've described? It seems like it might be something loose. Just not sure where to start. Any and all are appreciated!

 

[Bladecutter]

I have a 68 GTX with a factory tach as part of the instrument cluster. All the other instruments work fine but for some reason the tach just stopped working. It has always worked fine. Then a couple of months ago it got fickle and you had to tap on the plastic panel over it and it would start working again. Then it just stopped working period. When it worked it was accurate. I'm a little stumped - anyone have any idea what could cause what I've described? It seems like it might be something loose. Just not sure where to start. Any and all are appreciated!

K Man,,,electrical is not my forte' at all, but since it was intermittent before giving up, I'm guessing a bad ground. Good luck with it Bro.

 

[PurpleBeeper]

First thing check all the connections... hot, signal from "-" side of coil & ground.

 

[oldbee]

Go with purple's first. Then remember how old the tach is(!)my rally clock quit 15yrs ago.