Tach not working

[Superwrench]

Anybody have trouble with tach after putting in electronic ignition ? Been helping friend with his BJ8. Put new wood dash panels in. After installation, tach won't work and it did before removal. Talked to Nisonger and he asked if he has electronic ignition in it ? He said that could cause it ? The electronic ignition has been in this car for 4 years. I have checked wiring and grounds and it should work. Any help will be appreciated ! Thanks !

 

[Keoke]

If possible switch dizzy to another car and see if it works it could have failed for some obscure reason????
Be sure the pick up loop is correct.

If it works in the other car check your installation again.
OR: you may have to update the Tach.

 

[steveg]

See this thread:
https://www.britishcarforum.com/bcf/showthread.php?90295-BJ8-Tachometer-problem&highlight=tachometer

Also see this pdf on healey6.com:
https://www.healey6.com/Technical/Werner/BJ8 Tachometer Reads High.pdf

 

[vette]

Seems to me that the electronic ignition has nothing to do with it, since the ignition and the tach have been working in the car together for 4 or more years. You know the old rule, if it worked before you changed things, and it doesn't work after you changed things, then it's something you did. Did you change polarity on the whole car which necessitates changing the connections on the back of the tach? Did you connect the tach exactly as it was before? Did you possibly short out the tach and cause internal damage. This is unlikely but possible.

 

[steveg]

In the thread and pdf referenced above the little wire loop thing on the back of the tach is mentioned as being able to be looped incorrectly, causing tach problems. Also a resistor on the back inside which goes bad.

 

[Keoke]

In the thread and pdf referenced above the little wire loop thing on the back of the tach is mentioned as being able to be looped incorrectly, causing tach problems. Also a resistor on the back inside which goes bad.

Yep absolutely right

 

[Patrick67BJ8]

In the thread and pdf referenced above the little wire loop thing on the back of the tach is mentioned as being able to be looped incorrectly, causing tach problems. Also a resistor on the back inside which goes bad.

my tach had problems, low reading, after my ground up restoration but none before with Pertronix. I was told to do a double loop on the backside connection, but I ended up sending it to Nisonger at about $300. They said it will now work with all electronic ignition systems. Be sure to check all Dizzy connections especially if you converted it to Neg ground. I even added another ground strap near the engine motor mount and frame on the Dizzy side.