@Old Jock I don't know enough about the tech side of charging systems, but might it be a possibility that Rickyx's battery is not 100% and has a higher internal resistance than normal and is dragging the voltage readings that he's taking across the battery's terminals down?
@CRYSTALJOHN you are quite right of course and know more than you let on Checking the alternator output is independent of the battery as you test the AC voltages on the yellow wires at various RPMS However I agree if trying to diagnose a charging fault especially just checking voltage at the battery the first thing to do (and I see it all the time over on the Guzzi forum) is to get the battery out the bike charge it, let it sit for an hour or 2 then measure the Open Circuit resting voltage annd that should correspond to the spec, I think around 13.5 off me head, but certainly better than 13V. Then bang it back in and start to do checks. If the battery is so much as discharged let alone on the way out, it can pull the voltages down as the battery acts as a sort of reservoir or damper within the system. I'm no expert either just a happy amateur, perhaps @AirCon willl pop up later and grace us mere mortals with his words of wisdom John
Just in case... I just bought a Shindengen FH020AA Rectifier plus Triumph loom-ette. My money is on it being the Reg/Rectifier as it always has been on the 3 bikes I've had with charging problems.
Took the battery box off Removed old R/R Re-routed fuel pump solenoid while I was there MOSFET R/R too big to fit where original was Made a bracket out of carbon I had lying around Installed 14.4V at 4k rpm (not shown on pic) Yay!
That’s a bit of styling to show I got a carbon bracket... You’re right....it looks shit but I wanted to get it done and tested!
Could you show/explain how the wiring goes to the new connectors. From the Original 749r connector to the new setup. Would also like to modify my rectifier but having dificulties with the wiring. thanks
Once the battery box is removed, you can see the existing R/R wiring. Disconnect it from the old unit, remove unit and chuck in the bin/ put on eBay. The new Triumph loom connects to this using the existing connector blocks EXCEPT the generator block (yellow wires) needs to be tie wrapped to secure it. Then, just carefully route it upwards so it comes out of the battery box. I undid the Triumph loom as it is taped together as I felt the two main loom parts sat better the other way around. When refitting the heat shield it can be gently bent around the new loom so it all fits snug. Sorry I haven’t got a pic and I ain’t taking it apart again to show you so I hope this will suffice!
An aluminium base plate would be a better dissipater of heat, which is what usually does for Reg/Rec although not such a problem for MOSFET
Interesting point. Glass fibre is a relatively inert insulator I think but I’m not so sure about carbon fibre. I know it’s quite active in terms of electrolytic corrosion and that solid carbon is a conductor of electricity. Conductors of electricity are often conductors of heat too, so maybe it’s not such a bad thing to use after all??
I did consider an ally plate for its heat sink properties but opted to use the carbon because: a) It was just there on my shelf b) it was thin and easy to cut and file c) it was already predrilled for the hose clips (it had been used as a PC111 mount on my trackbike) d) It was lightweight e) The MOSFET RR runs cooler and the location was further away from the shittest place in the world that Ducati sited the original RR f) It scores higher on the bling-o-meter!
Nevertheless, we are still going to have to see your workings. Rip it all apart and take pics, thanks.
