Without having the black wire from the R/R connected to anything?
I have probably tested them all through troubleshooting, but for the sake of getting the electromag/field coil functioning I'm eliminating the harness by going direct from battery/ground into the R/R and through the stator/coil without any success.crazypj said:Have you tested wiring harness for continuity? Yamaha were notorious for having bundles of wires crimped together inside harness, one could easily have broken after 35~40 yrs. The XS wasn't as bad as the smaller bikes, they often needed replacement harnesses before they could be sold (un-crate, put a battery on it, do a warranty claim : ) The worst were the intermittent faults, may work for months then just stop. Spent many hours fault finding on Yamaha's (Suzuki's were easy, almost always blown R/R, and stator after owner fitted a new battery without testing anything)
A bit too early to call it just yet, but something isn't adding up. How many amps is the fuse rated at? Any resistance between the brown field coil wire and ground?Garc said:So we have battery voltage on the white wire through the R/R following your wiring diagram.
Pulling the power from black signal removes 12V from white.
Going to brown on the field coil with the white wire and green/green creates a spark that blows my signal 12VDC fuse.
Between green and brown on the 3 plug field coil we had 3.6 ohms both ways. We already proved those were the 2 windings.
Is the alternator bad or the Rectifier/Regulator?
Exactly. But if there is low resistance between the field coil brown wire and ground, then this would be the cause of the fuse popping.crazypj said:There shouldn't be continuity between Brown and ground, until you have the other end of coil plugged into harness