Too wet out there today (bent over in a thunderstorm isn't my idea of fun), so reduced to playing with what we've already taken off.
Cleaning / painting engine parts is the wife's job as she has the patience for it, plus I am slightly fitter for climbing head first into engine bays so leaving the rocker covers, plenum chamber and upper manifold for her.
Alternator is off though for better access, and had had relatively poor charging. So thought I would have a look at tracking down a 14.7v set point regulator. Hoped I had found one after some trawling about, not helped by the total absence of any stampings / labels / codes on anything on my alternator. Google image search eventually matched it to the Denso 127-120 though.
Set to dismantling to double check. Plastic cover a pain to get off because of the weird folded over double washers. Got it off and measured. 68.5mm between main mounts, one I had traced was only 56.3 so back to the drawing board. On the other hand in the course of checking everything I could (hit a brick wall at slim line 5.5mm socket, not got one of them), I discovered that the nut under the main power output cable, you know, the 120Amp feed to starter and battery was slightly loose. Now the top nut would clamp that cable to there no problem, so no issue at the feed out, but under that nut is a terminal and tail that feeds down into the depths of the alternator - possibly the star wire connection if that is the configuration? Can't imagine that being loose and jumping about does anything for consistent and accurate alternator operation / output. All tightened, but obviously until the engine is done I can't see if there is any difference.
From what I can see on the wiring diagrams, the feed for the battery voltage comes direct from BECM, so I don't know what would happen if you tried to tinker with that.
On the Guzzi in the past I had poor charging when the regulator feed came straight from the battery. Taking the feed from a switched live but load bearing circuit instead meant the signal was lower, so the regulator compensated and effectively set the charge voltage a little higher. I don't know how much drain comes down that wire, but might putting a load in it have a similar effect? Suppress notified voltage (say by 0.5v) and lead to an effective bump in the set voltage by the same? Or would the load burn the BECM circuits? Or could a separate feed from a loaded live circuit do the same, possibly via a relay so the BECM still sees itself as switching something?
Thoughts? (No doubt starting with 'You want to add more complexity to a P38 wiring set up? You loony!).
