Re: Ground Problem?

[billw]

Fleetwin mentioned the voltage drop test. This is hard for some people to wrap their head around, so think about this for a few minutes, before you try it:

First, ohm readings in a starter circuit are usually useless because you’re testing the circuit with a 1 1/2 volt battery and almost no amperage. You really have to test a starter system under load.

Voltage drop tests can test parts of the circuit, individually. What you are trying to see is how much LOSS of voltage each part of the circuit has, through any given component. In the case of the starter solenoid, you would test by putting the negative lead of a volt meter the starter motor side of the solenoid and the positive lead of the volt meter on the input, battery side of the solenoid, WHILE CRANKING the engine. Believe it or not, this will read a voltage, hopefully small. (BEFORE cranking, it should read battery voltage.) It indicates how much is LOST through the solenoid, before ever getting to the starter. If it’s more than say, half a volt, while trying to crank the engine, you probably have a solenoid problem. This is the tip of the voltage drop test iceberg; there is a lot more to test. But since you are focused on the solenoid right now, this is the best way to test it.

Long live American manufacturing!