Many, many thanks to nixon@norcross.mcs.slb.com (Alex Nixon) for his input
on my tachometer. It turns out that its signal feed was wired incorrectly
to the positive side of my ignition coil. This is on a '73 Stag, BTW.
Imagine my delight when I started the engine up and the needle immediately
jumped up to 900 RPM! First time it had ever done that. Problem is,
that's all it will do. When I rev the engine, the needle ekes up to about
1,000, even if engine goes up to several thousand RPM. Also, the needle
stays put after turning the car off. I've taken the unit apart, all parts
are moving freely, and I've even lubricated the mechanical part with light
oil. Have tried all positions of what I presume is an adjusting rheostat,
but the tach doesn't repond differently at any setting.
Is my tach broken? The manual says that it is very polarity-sensitive, and
it was certainly wired with the incorrect polarity by a PO. Anybody with
experience re: the damage that (may) have been caused by incorrect wiring,
and how to fix it?
|