correct volts C2

[Don 42616]

I have an e bay new volt meter (I am becoming high tech,). At idle Battery shows 12.48V coil 12.50V alternator 12.40V resistor -2.25V ???
I don't understand the later read. Don

[William C.]

Re: correct volts C2

Due to the pulsed current (points open and close-no steady state) the resistor is seeing when the engine is running, voltage cannot be measured at this point

[Stephen L.]

Re: correct volts C2

IF the engine was not running (Key was on) the points could have been closed. This completes the circuitry to ground with the resistor and coil in a series connection. You will then be looking at a voltage divider...
Battery voltage-resistor-coil-points-ground. Try it with the engine running and see if there is an increase in voltage at the SAME point on the resistor...somewhere around 7-8 volts.

[Duke W.]

Re: correct volts C2

Idle voltage should be 13.5-14.5. A fully charge battery is about 12.5.

It sounds like the alternator has no or weak output.

Duke