Field Coil/Charging problem...

[lukeralsteen]

Hey James

I am having this exact same issue with my 77 750F.

How did you solve it in the end? I am going crazy trying to find and fix the problem and any help would be appreciated.

I am replacing the main harness today to see if that helps or not.

Please let me know.

[SeanFD]

The white wire conveys the voltage status of the battery to the field coil. Under normal circumstances it goes through the regulator to do this. I think you need to bypass the regulator and see if the battery gets charge; if it does the regulator is faulty.

I think, with your combined RR you have to leave it connected and then run a jumper from the white terminal to the battery +ve terminal.

Run the engine to 2000rpm max. If the battery is charging, the regulator is faulty.

The other thing you could do is buy a copy of the book that BigAl copied the simplified wiring diagram from. You can find it here:

https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book