Le Mans Mk2 Charging warning light

Hello all, I have recently purchased a Le Mans MK2 (first Guzzi !). I am currently fitting a Reg Rec unit (JMP) bought from Gutsibits to replace the original regulator and rectifier units.
My question to the forum is when I fit the new reg rec unit, I am unsure where to connect the wire from the generator warning lamp. This originally went to the rectifier unit but now there seems to be no connection for this wire for the new reg rec unit. Do I now not need this (although will have no warning lamp) or is this needed for the correct operation of the Bosch alternator ? If so, where do I connect it to ? Any help will be greatly appreciated.

Hello Denecrest, and welcome to the forum. Is there a wiring diagram for your new Reg Rec unit? If so please post it on here so we can get a better idea of what is happening.

Best wishes Chris

Hi Chris, thanks for getting back to me. As I am a new user it seems I cannot upload documents however below is link from Gutsibits website.
BoschNewTypeInstructions.pdf (gutsibits.co.uk).

Thanks

If this does make the charge light on the bike redundant (at first glance, it seems to), it’s probably worth getting a bluetooth battery voltage monitor - they’re very inexpensive. It’ll give you peace of mind that the battery’s charging properly.

Nick

It appears that there is no connection to the generator light on the dashboard. On the original set up this is a blue wire from the rectifier terminal 61

This system doesn’t seem to feature a charge warning light, but the Le-Mans 2 does have a built in Voltmeter in the dash so you can still keep a good eye on the charging status.
The new system does have connections to terminals D & DF which presumably feed power to energise the rotor.

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That’s what I thought, I will wire as per the diagram and see what happens

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The negative end of the bulb would normally go to DF, which is rotor winding positive, and there would be no Voltage on here while engine is stationary, so it would light up. I suspect the JMP reg puts Voltage onto the rotor as soon as it’s turned on, so bulb will never light. Could try connecting the bulb to there just to see what happens.

Can I ask why you changed the regulator?

Footnote: I’ve had the Voltmeters from both Spada 1 and LM2, I tested the latter with a variable power supply and comparing it against a high quality DMM (a Fluke), it was quite accurate.

The battery was getting charged at 17v at about 3000 revs. I’ve just got the bike and had original regulator and diode board. Thought best to change to modern reg rec unit

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OK thanks. Yep 17V is no good. Regulator fault by the sound of it. For mine I opted for an electronic regulator originally intended for BMW. Mind you the charge light couldn’t get it booted up so I had to add a resistor in series.