I’m in the middle of a complete restore of a T3 and am now at the stage of rewiring from scratch. Has anyone fitted a m-Unit V.2 instead of the fuse box and, if so, do they think it was money well spent?
Can’t say I ever have. A mate had his spada rewired by Towzer - Electrician from Nottingham and that was very neatly done with plug in relays and trip type fuses in place of the old stuff. Technology has moved on since the T3 was made, you may as well make the best of the job and use some of the new kit.
Ruper Paul did my cafe racer jobbie with Motogadget throughout including the M unit. His company is Rupes Rewires.
It’s the Zagato Guzzi on this page http://rupesrewires.com/category/recent-jobs/
Click on it to see the work and a wiring diagram .
Brian
OldRat and Don_Spada - thanks for taking the time to reply. Useful info.
my Spada was rewired by Towzer in long eaton i was very impressed with it
modern thin wall wiring made the look 1/2 the diameter it was and the new thinwall carries more current per size compared to old stuff - fuses were all replaced with a neat modern blade type box and i had the actual trip switches fitted - just press to reset
was done with miniature relays for everything that took a decent loading it was a one off job as all switch gear was new kawasaki zr6 (i think) and it was keyless ignition off the cat one alarm and i thought very good price
I have drawn a coloured T3 wiring diagram if you would like a copy. I suppose that is only relevant if you intend to use the existing wiring layout.
I rewired my bike and added relays for all handlebar switches, start, horns and including high/dip beam and the main light switch so there were no high currents going through the switches. seed to work well, only problem is that the bike has been off the road for ages after a main bearing failure. 
I rewired my T3 using a Rowe PDM60 electronic fuse box. It has some advantages over the M-Unit but does not include a starter relay, which is why I have chosen the M-Unit for my next project (a California Special Sport that is going to have carbs and a Sasche ignition amongst other things).
The M-Unit appears to be very easy to use and there are a number of add-ons such as the trendy looking push button switch units and the m-button for minimalists.
The earth sensing switching means you can use any handlebar switch gear without having to bother about current ratings which is a big advantage over the PDM60 and any standard fuse box.
There are a number of good ‘how to’ videos on You Tube showing how to get going. I decided on the M-Unit after watching a few of those.
MotoGadget stuff is generally pretty good. The M-Unit may be pricey but it will make the re-wire a lot easier.
On the T3 there won’t be many advantages over a standard fuse box, other than removing all relays, adding an alarm and making fault finding a lot simpler.
On the Cali it will vastly simplify things as it has a car type harness and uses relays for everything.
Hope this helps, even if a bit late.
Bit late to join in but if you’re anywhere near South London Steve Bikewire in Croydon is very highly recommended. He completely rewired my Mk1 and rewired my MK5 bstrd using all motogadget.
I know of 7 other Guzzis he has rewired and everyone is very happy with him.
AND he is VERY reasonable, less than half the price of other quotes I have seen.
He is also a really top bloke, cannot recommend him highly enough:
steve.bikewire@googlemail.com