Slow Crank, No Start When Warm
Voltage drop when cold between starter+ and battery+ while cranking was 0.94 and between battery- and starter case was 0.36. I didn't even bother warming it up. Would this be bad connections or wires?
You have to check and find out!!!
Voltage drop is just like a diagram---follows a road, follows a road map. If you hit a chuckhole (bad connection at a terminal) that is a drop right at the terminal. If you hit a narrow road (long length of wire) that is drop over a distance/ length of wire. How to check? Use your head
Once again, I suggest rigging up a remote switch long enough that you can reach the full length of from the battery to the starter.
"Let's say" you suspect a battery terminal/ clamp. First crank the engine and either feel it for overly warm, or use a "gun" thermometer. And or, clip your meter to the rear of the clamp, or stab a probe to the rear of the clamp, and stab the other probe into the top of the battery POST. Crank and read while cranking.
If you have a soldered/ crimped say, bolt on eye, like a ground, clip or stab a probe into the eye as close to the stud as you can get, and stab the other probe into the wire itself right next to the terminal. Crank and read.
Or maybe it's a rusty/ loose eyelet to ground stud. Stab/ clip a probe to the eye, and stab a probe "hard" into the metal next to the ground stud. crank and read.
Here's an example that threw me
Used to have a 86 Ranger. Ground cable went down next to the frame, where a factory "T" crimp in the middle of the ground cable, bolted to the frame. The cable continued on and bolted to the block.
One day it would not start, yet in the dim carport, the headlights remained bright. WTF? The voltmeter tells the story. A few checks and 15 min later I KNEW it HAD to be a bad cable. Cut the insulation around that "T" splice and there it was, cable all ate up and corroded inside the insulation.
Once you guys learn/ teach yourself a bit of power/ amperage/ voltage drop stuff, you can save a LOT of money throwing parts and money at a problem, and maybe even some time.
Ohmeters are not that much help sometimes, specially on large current type components.