My tach doesn't read
rpm all the time. The problem started last year and when onto the "when I get around to it list". I'm had the same type of problem in the past and it was just some
corrosion on the wire terminals for the
sensor so the other day I cleaned those.
But this problem is different and I don't really understand why it would do what it it doing. The tach reads fine on start-up when the
engine is cold. But after the
engine warms up it just reads zero. So it seems that the issue is a temperature related one. I can not believe that the wires themselves could possibly heat up enough to result in enough resistance to stop the
current for the
sensor.
Since it works on cold start-up I feel I can disregard a lot of the troubleshooting items such as voltage to the unit,
wiring connecions etc. And the only other thing to check would be using a syroscope (which I don't have anyway) when the engine is running and warms up to check the output of the snesor.
Is it possibe that the flywheel sensor itself could heat up a point that it stops working?
Anyone else ever seen this as I hate replacing sensors based on the "if" principle of troubleshooting?
PS - the circuit has nothing to do with the
alternator and has nothng to do with
charging.