That was my thought also. Just trying to find what the reading should be.
Reading should be open-loop/no continuity/infinite ohms like measuring resistance of piece of wood. Shown on many meters as "OL" or "1". Meaning power-wire has no connection to ground.
What you'll measure is short-circuit which measures very low resistance such as 0.01 ohms or 0.20 ohms. Meaning some section of that power circuit is connected directly to ground without going through bulb 1st.
Through process of elimination by disconnecting sections of circuit, we can narrow down bad section. When you disconnect it, meter will go from low ohms (short-circuit) to infinite ohms/open-loop/no continuity. Then you know problem is between that junction you just disconnected and previous one.
Trick is to measure resistance without blowing fuse. This can be done by pulling fuse. But still need to trigger relays to connect headlight circuits. Then measure resistance between chassis-ground to power-wire after fuse. Will show short-circuit/low ohms
1. then disconnect bulb, does resistance change to open-loop?
2. then work upstream on power wire and disconnect next junction. does resistance change to open-loop?
3. trace upstream to next junction and unplug. does resistance change to open-loop?
Reason we measure is because we're not Superman and can see electrons moving inside wires. No human can just look at wire and determine its ability to conduct electricity. Luckily, we have instruments that can.