First my apologies for disappearing without a trace. I had to get on a plane to the UK as my father was dying, which was expected. Anyway I have now returned to the islands and have checked the site to see that a number of people have responded with helpful suggestions. I had removed the POS battery lead overnight without any effect and I cleaned both brass connectors on the leads and battery with a Dremel wire brush. The battery is only about six months old a Yaesu and the volts read fine at 12.9v with the ignition off without the engine running and then rises to 14/14.2v when running across a wide rev range. With a 40 amp alternator the battery should not be being asked for anything unless the ABS cuts in and even then the alternator should be able to supply most if not all. Thanks for the ABS motor fuse location the fuse was fine. I have a 2010 original Yamaha shop manual and I cannot find the diagram that you have sent me, but yes idiot, it was staring me right in the face but covered with little sealing caps. I have just performed the hydraulic unit tests in section 4-72 both test 1 and 2. Test 1 First install the diagnostic test lead turn on the ignition and operate both levers and hold for the duration of the test. The first test ran fine the hydraulic motor running with a sequence of pluses on the brake lever followed by the pedal and then the front lever again. The second test turn the kill switch off, turn the ignition on, press and hold the start button for more than four seconds then operate both levers together. This test also produced the same results motor running first brake lever then foot pedal then brake lever then motor stop. This was repeated for test 2 and the same result was achieved. When the test was run for the third time, nothing! I tried the first test again and nothing. I then tried starting the bike and the relay just clicked and then on the third or fourth push it cranked but did not want to fire. I immediately measured the battery voltage 12.9/13v switched off. I tried starting it again and the same clicks and then turning the engine over kinda lazy it eventually it fired up. I had ridden the bike today and started it six times during the course of my journey with no hint of a problem. The starter has always sounded as if it was struggling a bit but it never failed to fire by the first or second rotation. I will take it to my shop tomorrow and start digging for the electrical connections starting with the frame and ABS grounds. Before that just for what it’s worth I will connect it up to a jump pack and repeat the hydraulic motor tests, after all that motor has a 30 amp fuse but it still makes no sense that the diagnostics refuses to give up the idea that it is the front brake pressure sensor. Perhaps I should also put the jump pack in the top box and run a couple of #10 wires between it and the positive and a new engine frame ground, and take it for a run it cannot hurt. The sensors have been cleaned and the wiring checked carefully where it could have been nicked or chaffed. Yes it’s a wake up call, time to change the fluid, I will check the pads but with just under 6K on it I doubt that they will be shot. I am hoping that it is something as daft as a ground but I am also leaning towards a connection between cells in the battery itself. Presumably the ABS controller can log a fault in a fraction of a second so if my battery internal connections go iffy this might account for an over voltage reading in the split second that it took the regulator to react as my first ABS diagnostics disclosed. The other thing is that after the bike has sat it can take anything from the first 100 yards to 5 miles for the ABS light to stay on. Has anyone used a lithium battery, if so how did you get on and how does the standard lead acid charging system suit the lithium?
