BJ8 tachometer fix

[shorn]

I was having intermittent problems with my tachometer. Sometimes the tach would drop back to zero when reaching about 3000 rpm's. The tach would also read high. This problem seemed worse in hot weather. When I installed a pertronix ignitor, the tach didn't work at all. First, I put a second loop in the ignition-coil wire at the back of the tach (had to use slightly smaller wire to get a second loop, but that only returned the tach to running high and sometimes dropping to zero. Took advice about a bad ground, but the tach seemed to work even w/o the ground wire attached. I think the light also has a ground wire so that probably completed the circuit. So the next step was to either send it to repair (Nosingers or MoMa) for about $120, or being inquisitive (either too smart for my own good or just plain dumb), I decided to open the tach up instead. Lots of neat little electronic parts in there, a circuit board, little tube type things with lines, some with numbers, none which I could read. Jim Werner's Healey site hometown.aol.com/bgahc/jimwerner.html gave some great advice about replacing a leaky capacitor which could cause the problem. Not knowing a capacitor from a diode, it was off to Radio Shack with tach in hand and a schematic. The guy was quickly able to identify the .22 uF capacitor and sold me a new one for $1.50. Five minutes with the solder gun and the tach works just great, although I had to reajust the pot at the back of the tach. This was pretty easy. Just be careful with the solder gun. Things in the tach are kind of delicate. /ubbthreads/images/graemlins/cheers.gif

 

[Bugeye58]

And look at the satisfaction you got from doing it yourself, Skip!
More LBC owners should be like that, rather than just grabbing the checkbook.
Jeff

 

[stever]

Bravo!!! Now every time you take a glance at your RPM's you will get a "warm, fuzzy" feeling inside! Great job, and thanks for sharing it with us!