I have a '66 442 with the stock tach up on the Left side of the dash. I have had an electronic shop check it out and they said it should work.
When I start the car it works for about a minute or so and then quits. I thought it was a ground problem but if it works and then quits it probably isn't.

Could someone offer some advice.

thanks

Pat Mills(Mr.)

 

Bad connection at the least. You might pop it apart and see if the lands or solder joints are damaged. Worst case a component part is acting up.

 

Is this a symptom that just started? Shot in the dark, but have you changed out the inline fuse? If that doesn't cure it, (and it probably won't) you most likely have a small part in the tach that is failing as it warms up. The innards are electronic and 50 year old parts can fail. You may need to send it in to have it worked on.

 

thanks for the advice.