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