<VV> '63 Spyder - Tach stopped working

[Larry Forman]

At 09:56 PM 5/26/2004 -0600, Blaine Sanders wrote:
>The tachometer in my '63 Spyder was working just fine the other day.  Then
>my buddy was playing around with the timing and next thing I know the tach
>has stopped working correctly.  To be more precise, the needle still moves,
>but it won't go over about 1,200 RPM's.  Any idea what could be causing
>this?  I checked the connection at the coil & it seems fine.
>
>Thanks in advance,
>
>Blaine
Hi Blaine,
I am not sure how you checked it.  If you did the check visually, then I 
would check it electronically, which is what the tach sees.  I would take a 
multimeter and measure the voltage at the negative lead of the ignition 
coil and also at the tach input.  I would also recommend installing an 
additional grounding wire to the dash.  You could ground it to one of the 
gauges on the back of the dash and then to a screw on the sub-dash mounting 
sheetmetal.  For the Late Corsas and Monzas you can ground it to the same 
screw that holds the turn signal flasher.  I used 14 gauge wire which is 
overkill, but it really grounds the dash well.

You can also measure the voltage with the key on and at various rotations 
of the crankshaft, which will ground and unground the points.  Just measure 
at the ignition coil negative lead and the tach input, which should be the 
same wire connection.

Larry