650 main fuse blowing

I just swapped the stock fuse box for a blade fuse box, that was no issue. One thing I did find was when I went to do so, previous owner had bypassed fuses for main, ignition, and signal; one of the latter two was still fused with inline fuse though, not sure which. The other one, along with the main fuse, was bypassed and wires were directly spliced together. I corrected that, and hooked up with fuse box.

The moment I connect battery the main fuse blows. I started with 20A as the oem box listed. Pop. 25A, 30A also both popped.

Disconnected rectifier, tested diodes. All passed. Could the cdi be causing this, or where should I be looking instead?


This wire (black with red tracer) that looks like it should be connected to starter is spliced back to itself. The diagram I have showed Black/red tracer as being oil level light, which at least to me doesn't explain why that could be causing main fuse to instantly blow. As it is currently wired, there's nothing connecting to spot 3 on the cdi (as illustrated in the same picture)

Any pointers on what direction to go? (And yes, buying a new harness isn't out of the question if that would fix it... I've got a list of parts I'm going to just replace rather than try to fix myself right now. I'd rather get riding my first bike than spend the whole summer fixing it. I'll have all winter to deep dive and learn. )

 

The TCI should not get power until the ignition key is switched to "ON" and the kill switch is set to "RUN"

I looked back and you were trying to start the bike before you did this work, perhaps you have connected something that has caused the fuse to blow

Some pictures of the fuse box might help and any non stock features to the bike

Why are you concerned with the B/R wire? Per the drawing a bullet connector like you have pictured connects the oil level switch to the main harness

This is a 750, but should be wired the same so all looks normal

 

That is good to hear. I didn't know if I should be concerned, that's all.

I think it's something to do with the rectifier. Found another thread on here where it was discussed that the main fuse connects to ignition switch and rectifier. Suggested unplugging them, putting power back to system; if new fuse blows it's a short in harness. I unhooked the rectifier and left the ignition switch connected, new 20A fuse, and connected battery. No pop. Then I connected the rectifier again and it popped instantly. I'm buying a new one (and a new harness too, just to cover my bases). Rectifier diodes didn't fail, but I really think it's due to that.

 

Does Anybody have bare bone wiring Diagram for 1981 xj650?

 

This thread has links to wiring diagrams.

https://xjbikes.com/forums/threads/high-res-pdf-of-xj650-wiring-harness-diagram.44033/#post-653809