Quote:
Originally Posted by Aran
Anyhow, I didn't have my phone handy on me to look up what I needed to do for proper testing so I was doing power-on voltage testing since that was the first thing that came to mind, and engine off all the circuits I tested, when powered, were showing 12.x volts, and engine on 13.x volts, which is likely a completely useless point of data.
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This is very good, you're halfway there with testing! Review this:
https://www.ifixit.com/Guide/How+To+...ltimeter/25632
Now, you want to test all those +12v wire again. But this time for resistance.
1. Key OFF
2. set meter to measure resistance (ohms) on lowest scale
3. clip negative probe to ground-wire bolted to chassis
4. Trace along (look with eyeballs) every inch of each +12v wire for melted or scratched insulation. Yes, you have to slice open the loom wrapper. Poke through insulation every couple of inches with other probe. What is resistance to ground?
5. have assistant wiggle wiring when you test points in #4. Does resistance to ground change?
Ideally you have infinite resistance to ground on +12v wire with key OFF. Most meters show this as "1" or "-" or something on left of display. If there's ANY resistance displayed, 3.5, 1.2, 0.5 ohms, etc. you've got a short on that section of wire and ground. You find that short by probing for low-resistance/continuity every couple of inches along wire from one end to the other.
You're almost there. Just have to repeat this test with key OFF and measure for continuity.