Hi,

You are going to be checking out the cables themselves. You will unhooked them from the battery completely.
I would unhooked the alternator's big red wire as well.
We will concentrate on the positive side of the cars system.

The ohmmeter is going to apply its own battery voltage through the cable from end to end.
It will convert that voltage reading into a resistance reading. A good cable will read a very low number almost all zero's. Like 0.08. A very low resistance or a short is the same as if the leads were held together.

The meter number should "not change at all" if you go from one end of a positive side cable end with one lead and the other lead touching bare metal on a grounding spot on the car.
The needle should not move on an analog meter and on a digital meter, it will show only the numeral "one." Like 1. And blink.

You want to see an open lead reading "to ground" on positive side cable when unhooked like this.
This is done with the leads on each end or from the mid point at the starter as you just said.
This way you divide the problem in half each way to the ends of the cable.
If there is a bare spot touching ground some place it will be on one or the other from the middle if you have to break it below.

The ohmeter is not very accurate to tell you how much resistance there is on very large cables. In this case of troubleshooting it's not necessary. You are looking for a direct short and hopefully on one side of the starter. Up to the battery or over to the alternator via under the engine.

You can also check the alternator stud to a ground or its housing if there is a cable on the housing going to the engine. There has to be one on there for the cluster warning light to work. That build in the cluster and gives the exciter diodes a little tickle or jump start through the rotor so the regulator can take over.
When the alternator outputs a small voltage, it opposes the battery voltage coming in from the light and it goes out.
It does not take much to turn the light out. So, it does not mean all is working great as these are called idiot lights
A dash type voltmeter is your best indicator, as it will tell you how much more above the battery voltage, the regulator is giving to the "SYSTEM."
A fully charged Battery is 12.65 and it needs at least a .5 volt to 1.5 volts above that to keep a battery maintained.

When get things straightened out take voltage readings on the battery posts with various items on in the car to see if the charging system is up to a 13.2 to even 14.2 volts on a semi to fully charged battery.

If you do not get good voltage readings all is not lost with just an alternator.
Sometime excessive corrosion inside terminals or under insulation of wires can cause a high resistance or voltage drop. This will throw off the feed back and output of the alternator.
In these cases there is another way to use a voltmeter to find out and where this can be in a cars system. Of course that is another chapter in troubleshooting for different reasons.

A multimeter is your friend because it can see electricity. That is, when you understand how to use the leads and the function dial.
It make working on these parts of the car more fun than just knuckle busting.

Thanks for the feed back. It's nice to know you are on it.
A Turkey Dinner is a good motivator.

Phil