[Healeys] Tach heat sensitive?

[Greg Mandas]

Just a swag here, but my mechanic says my tach is running high because the
wire the tach reads is old and therefore has higher resistance (?EE's?) He
says he typically runs a new wire, therefore with lower resistance, o fix the
problem, barring a complete harness replacement.

That being said, and the
fact a warmer wire has higher resistance, sounds like it should run higher at
warmer temps.

Sound Right?

Greg
65BJ8  

> 
> On 8/18/11, Tom
<ah3000me at gmail.com>
> wrote:
> > I've noticed that when I drive to work in
the morning
> when it's cool
> > (50-60F), my tach shows about 2500 RPM at 65
> MPH.  When I return home at
> > night when it's warm (80+ F), my tach shows
about 3000
> RPM at 65 MPH.
> >
> > Any ideas about what's going on?
> >
> >
thanks,
> >
> > Tom
> > _______________________________________________