I did a web search on this and all I'm getting is results about parasitic draw, i.e. bad starters draining batteries while parked. I have a friend whose starter cranks slowly and I was sure that her battery was dying until I tested the battery with my load tester and it passed more than once. I had her start the car with my multimeter reading the battery voltage and it dropped to about 9-10V while she cranked the starter. I have no idea whether this is normal, first time I've checked it like that.
I suspect that her starter is drawing too much juice and will die at an inopportune time. Of course, I know that I can remove the starter and have it tested somewhere independently from the vehicle but I'm busy as hell and would love to test it on the car.
My knowledge of auto electrics reaches to testing batteries and alternators with my multimeter and load tester and finding bad grounds occasionally, beyond that I'm lost.
So...I do know that it's all about amperage with things like starters but I don't know how many amps it's supposed to draw or really how to test that. I'm sure it's on my multimeter somewhere. Awaiting smarter electric people.
Car is a 2009 Suzuki and owner is going through a tough time so trying to help if possible without just throwing parts at it or putting it in a shop. TIA.