My 1969 series 2 has an intermittent failure of the Tachometer.
The engine runs smooth, but on hot summer days the Tach fails completely, it does come back up occasionally but fails constantly.
in the cooler weather it seems to work fine.
i checked out the wiring and it seems fine, my understanding is that, if the engine is running smooth, there is little chance of a wiring issue.
when the Tach is running it behaves well with no jumping around.
i have read that the capacitor and transistors can be replaced. Can anybody throw any light on which one of the ( if either ) is failing.
i am not an electronics person but have enough skill to replace both if required.

 

Sorry I did not realize that this issue had been responded to by David.
i just missed the reply