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R26 Replacement Voltage Regulator Wiring

Posted: Fri May 20, 2022 12:55 pm
by sblaylock
I have a new electronic VR I'm installing in an R26 and I need some help with the connections.

I have two sets of directions and they don't seem to align:

This one shows D+ as "Free":
20220519_183752.jpg
This one shows 61 as not connected:
20160601_154221.jpg
This is a photo of the board and wires:
20220519_182643.jpg
Assumptions and questions:
The connectors on the board from Left to right - 61, 51, 30, 15.
B+ should be connected to 51 or 30 as they are tied together on the back side of the board.
DF should connect to the melted yellow from the generator.

That leaves D+ and 61 in question. Also, there's a mention of "removing the field resistor from earth"? Does that apply it the R26 and where is it if it needs to be removed.

There is another yellow wire coming from the top that was attached to the top RH screw holding the old VR (see red arrow). I'm assuming it will go in the same place on the new install.
2022-05-20_9-53-37.gif
Thanks for the help,
Scott.

Re: R26 Replacement Voltage Regulator Wiring

Posted: Fri May 20, 2022 3:26 pm
by wa1nca
D+ and 61 are connected connected together on the terminal board
D+ is generator output
61 is for red charge light
D+ and 61 on the new regulator are also connected together so 61 on terminal board can go to either D+ or 61 on the new regulator

B+ on regulator to 30/51 on terminal board

DF on regulator to Yellow wire(you said was field wire)

I assume the other small yellow wire goes to the resistor built into the field coil and needs not to be connected
but would like to verify by other members

Re: R26 Replacement Voltage Regulator Wiring

Posted: Fri May 20, 2022 5:40 pm
by sblaylock
Hey Tommy,

D+ and 61 being connected makes complete sense as to why the difference in the instructions.

The wire I was referring to is the small yellow one in the top of the photo with the eyelet. I have no idea where it's going as I can't see behind the cover. The large yellow one below is the one I'm assuming goes to DF from the field windings.
20220520_142916.jpg
This is the preliminary wiring:
51 --> B+
D+ --> Empty
Yellow Wire from Generator --> DF
61 -- > 61

If I understand it correctly, the top yellow wire should be insulated as it's not used anymore.
20220520_162624.jpg
Hopefully this is correct,
Scott.

Re: R26 Replacement Voltage Regulator Wiring

Posted: Sat May 21, 2022 11:03 am
by wa1nca
The field coil on r24-r26 have a 3rd wire with a resistor built into the coil which is grounded
Yes the short yellow wire is not needed with the electronic regulator and should be capped off

https://bmwclassicmotorcycles.com/index ... oil-1.html
InkedInked20160601_154221_LI.jpg
Let us know if this fixed your charging issue
Tommy

Re: R26 Replacement Voltage Regulator Wiring

Posted: Tue May 24, 2022 11:38 am
by sblaylock
Hey Tommy,
Sorry for the late reply - long weekend in Canada.
Yes, it fixed the charging issue and I'm getting North of 7 Volts at the battery now.
Thanks again for the help,
Scott.