headlights not working
I cannot tell for sure "I guess" you have the probes correct in the bottom photo. You need to turn the selector switch to "ohms" to the lower right where it says "200" right next to the "diode" symbol
What model is the top one, I cannot tell
Demonic, above, mentioned color of wires. THIS IS IMPORTANT. The alternator output wire is a large BLACK. It most certainly is NOT ground, and IS NOT fuse protected. This same wire goes in through the bulkhead and connects to the ammeter.