Where is the regulator

[jrhowe]

Where is the charging regulator located on an 81 xs400 H. I can't find it or even what it looks like? Any help would be appreciated. thanks

 

[xschris]

Looks like this and is located on the battery box.

 

[jrhowe]

Looks like this and is located on the battery box.

Thanks xschris for the info and past info!!!! The bike is running great and running like a champ thanks to you and all other members here on the site. Just trying to get the charging volts down some.

 

[XSLeo]

If your charging a bit high on the voltage it might not be the regulator. The reg reads the battery voltage on the brown wire. With the key on check the battery voltage at the battery. Use this as a reference voltage, now check voltage at the brown wire at the reg. If it reads more than .2 or .3 below the battery you have a bad connection some where between the battery and reg. Or possibly a bad ground.
The reg is set to keep the battery at 14.5. If it reads 14.5 on the brown wire it will charge to that. If the brown wire voltage at the reg is 13.5 then the reg will try to charge the battery up get 14.5 at the brown wire, or a full volt over what it should be.
So do some testing before you start swapping parts. Often the main key switch is dirty and creates the voltage drop, Sometimes the main fuse. Other can be dirty connections where wires plug together.
Leo

 

[jrhowe]

If your charging a bit high on the voltage it might not be the regulator. The reg reads the battery voltage on the brown wire. With the key on check the battery voltage at the battery. Use this as a reference voltage, now check voltage at the brown wire at the reg. If it reads more than .2 or .3 below the battery you have a bad connection some where between the battery and reg. Or possibly a bad ground.
The reg is set to keep the battery at 14.5. If it reads 14.5 on the brown wire it will charge to that. If the brown wire voltage at the reg is 13.5 then the reg will try to charge the battery up get 14.5 at the brown wire, or a full volt over what it should be.
So do some testing before you start swapping parts. Often the main key switch is dirty and creates the voltage drop, Sometimes the main fuse. Other can be dirty connections where wires plug together.
Leo

Thanks guys I got it. I had the higher voltage at the end of last riding season and I forgot to check the connections. I had taken off the head light bucket to paint it and disconnected all the wires in there and put it back together last night. One of the wires in there must of had a bad connection because when I put it back together and started it up it was good. I had 14.8 vdc at 5000rmp and it didn't go any higher all good now! It snowed last night here in Ohio!!!! So much for spring!!!!!! At least I got out to ride twice for a couple of short rides so far.