Again just for reference, this is the value of the factory fitted charging resistor on my lemans 4, 69 ohms
1 Like
I was going to say, low resistance is notoriously difficult to measure, mainly due to tarnishing of the metal parts that you want to probe, and the probes themselves, a friend who used to be a technician for a cancer charity told me they would sharpen their meter probes until they’re like needles, so the sharp points could penetrate surface oxidation on connectors.
But like you my Fluke, that cost £250 second-hand 30 years ago 
- and from a mate at that - has an internal error of 0.2 Ohms so first thing I have to do is subtract that from any low resistance measurement.
1 Like
Fernando
It’s an old Guzzi, I don’t think there’s any need to worry about fractions of ohms.
It’s a pity you don’t live anywhere near Leeds as I’ve a complete charging system on the shelf and being able to substitute components is certainly the easiest way to fault find, after being a Jack of all trades maintenance engineer although mainly mechanical stuff and lots of hvac controls I may have learnt something just before I retired 
1 Like
Did you have the lights on when you did this test? That would drop the voltage.
1 Like
No lights on this test.
It would be a good idea to go through the various connections to make sure everything is nice and clean. The charging system is obviously working but not to its best capacity. Check things like the brushes to the alternator slip rings and all the electrical connections, including the big multi block connector under the tank.
The Charging around the circuit guide mentioned above is very good for describing how the system should work.
2 Likes
Just to add to that clean the fuse contacts and the bullet fuses. I have known them to pass no current!
3 Likes