New Rectifier blew right away..

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Okay, I have a new to me 75 XS 650b
Bike was not charging, killing the battery in 30 minutes or so..
The regulator checked out(as per manual)
but the connector to the regulator was hot..

The rectifier was showing no current through
any which way so i built a new one(radio shack)
and installed it. the bike was again not hardly charging
12.6 off.. 12.2 key on 12.4 revved up..

I checked the rectifer and blown again
no current through, any which way..

I checked the ohms between white wires of the stator
and it is correct. Any ideas?
 
but the connector to the regulator was hot..

The rectifier was showing no current through
any which way so i built a new one
...
I checked the rectifer and blown again
no current through, any which way..

I sort of suspect neither rectifier is blown. When a diode goes from over voltage it's usually like a little firecracker. Unsolder the Radio Shack bridge and test each diode to be sure.Connectors can get hot because of high resistance in them; the reason a light bulb glows instead of your house wiring.
 
okay, i took out the radio shack rectifier
and tested it, nothing..
it only has one lead left, and it seems like all three are blown
 
Look for an internal diagram of that bridge you have (I think there's one in the drawing you're using) and measure ohms one way then reverse the probes, for each separate diode. Should read high or open one way then low the other way, for each of the four diodes in it. That will test the R.S. rectifier, but I don't know much about the electronics for your year bike though.
 
To check a rectifier you hook the red lead from you ohm meter to the red wire, touch the other lead to each white. Now hook the black lead to the red wire touch the other to each white. Now do the same using the black wire. You should get a very low ohm reading one way and a very high reading the other way. The high reading should be at least 10 times the low reading.
On these bikes the high reading is around 700 ohms, the low reading is at or near zero.
If you look in the tech section at the top of the page you will find out how to check the charging system out.
Most likely the rotor or brushes are bad. Brushes around $20, rotor $125.
Doing a complete check will save you money by telling you whats bad. Then get the parts you need.
 
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