No Power + No Shorts = Bad Rectifier?

Hey everyone! I'm pretty new to the KZ world and, unfortunately, I'll have to kick off my membership on this board with a problem I need help solving.
I'm having a strange issue with my 1978 KZ400. I don't have much experience with these older electrical systems (or electrical systems altogether), so I was hoping for some advice from someone more experienced.

Bike was running fine all day yesterday. Today I turned it on for a few minutes to warm it up to check oil level. After 3 minutes it just shut off. Now, no lights or any power with key turned.

Here are the steps I took and what I found out:
1) Main fuse has power
2) The two other (10A) fuses have no power on EITHER side - with or without key turned
3) Replaced fuses just to be safe, same problem
4) Checked ignition switch as per manual. I have proper reading from ohmmeter - I've attached chart from manual for reference
5) I went back to the fuse box and did something perhaps not recommended. I created a bridge with some wire from the main fuse to the other fuses and everything started working again. Headlights came on, and I bumped the starter without a problem.
6) I figured since the last step work, it couldn't be a short on the other two circuits, but I traced the wires back and wasn't able to find a short.
That the the crux of the problem.

Out of desperation I checked the rectifier with an ohmmeter as per manual. I found that when the positive lead is held to either of the yellow wires, I get NO LOAD. The manual instructs that this connection must read below 20 Ohm (chart below). So here is my question: Is NO LOAD suggest a failure of the rectifier, or is it acceptable when the manual instructs that it must be under 20 Ohm? If it is a failure, would this explain have no power at the two 10A fuses?

I just cannot begin to wrap my head around this, so any suggestions would really help. I've also attached the wiring diagram if you can think of any other trouble spots I should check for having no power at all.

Thanks in advance!

>>>>>> Now, no lights or any power with key turned.
The coil is not getting 12 volts, causes dead battery, oxidized connections, crimps have failed, ignition switch failed.
Remove fuse holder, clean connectors, replace with jumper, report back here.
Your rectifier is likely ok.

The rectifier is part of the charging system and should not prevent the bike from starting. One thing you haven't mentioned is the condition of your battery. Did you test it for voltage? Your problem may be a bad generator that ultimately led to the battery running out of power. Another thing to check is the bike ground from the battery. It's the black cable and would likely attach to the engine somewhere. Is it clean and secure?

There are better people than me to provide advice on electrical stuff. Hopefully they chime in here.

Also check the battery itself to make sure it is still ok. Ed

Your key switch is in between your main fuse and the other fuses. I would suspect something around there.
Turn your key on and measure DC V between battery negative post and the white wire at the key switch.
Then move your positive meter lead to the brown wire at the switch and check the voltage there.
You want close to battery voltage at all those points. It may be half a volt less or close.

When you jumper wired the main fuse with the other fuses it was a clue that you have a break between the main fuse and the other fuses.

You can check these wires inside the headlight bucket at the connector circled in red on the schematic.

Measuring resistance at the switch is not a reliable method of checking it. You can have one tiny strand of wire and the switch will read good when it's actually bad. Corrosion or a bad connection can fool the meter if you use the resistance setting.

Thanks for all the help fellas. I got this problem resolved. There was strange, black corrosion at the very end of the fuse holder (right where it crimps into main wire). So It had charge at the on both sides of the fuse, but not at the very beginning of the wire. Strange how a little corrosion can cause such major issues so suddenly. Thanks for helping rule out the rectifier, I don't know what I was thinking there.