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Getting Started with Wiring


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Obviously I need to learn how to perform basic wiring repairs and tasks. In addition to the lighting and grounding issues with the V11, I would like to replace the dash and ignition switch on the T3 and add some running lights. There are a lot of areas of old electrician tape wrapped around the wiring on that bike, so I figure she’ll be needing some TLC.

Wiring is one area that I am totally green in, and looking around today to fix my headlight ground I realized that I have a multimeter and a wire cutter, and that’s it. So, I am planning to buy a crimping tool and some assorted connectors and wire to get started.

Any recommendations on good sources for this stuff? I know that Summit Racing sells wiring items.

I am also curious what style of connectors and wire are preferred to work with on these bikes? I know there are open barrel, closed barrel, insulated, non-insulated, some with heat shrink, 3.5mm, 4mm, etc., and 14g, 16g wire. I believe this will also determine what kind of crimping tool to buy.

I guess when your bikes get old enough you gotta take the leap and learn how to do this stuff. 
Any practical guidance to get started is much appreciated!



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Not an expert calling @Kiwi_Roy over!!!!

I've done a few wiring schemes from scratch but never an FI bike. My own experience is to go all metal non insulated crimp, with the separate plastic/rubber? covers. When I've used insulated crimps in the past they have tended to far less secure.

Tool I use most is a Hozan, but they cost more than most would want to pay


Also used something similar to these, with Ok results (not that particular tool, just one similar to it)


Stay away from this style of crimper


For multi connectors I use AMP style Superseal, but again these need another tool to crimp.............search around if you're only doing this once maybe a generous soul will loan you tools or assist. If you were in the UK I'd loan you some of my tools that you'd probably only use once if it's a custom. Guzzi owners seem to be a reliable, solid bunch and anything I've loaned has always been returned with much thanks

As far as wire you can usually get away with only a few sizes, use thinwall insulated cable, it carries a higher current for a given CSA. Run control cabling in 0.5 or 1mm^2 thinwall and power cable (for the majority of components, obviously not things like the starter or main battery terminals) 2mm^2 thinwall and you should be fine

You can purchase HeatShrink in packs of varying lengths and diameters, useful for sealing connectors if you're OCD and covering wiring splices if required.

@docc pointed out to me that the V11 has 2 looms one for the ECU/FI side and then another for the rest. I'd asses the FI side, it it's in reasonable nick I'd leave it alone, besides it's far less likey to have been tampered with.

My approach is spec what you want to do

Draw up or get a wiring diagram to cover what you're doing, so you have a clear plan

Purchase cabling/connectors/sleeving etc: based on the above

Layout the wiring onto the bike running all of it first, then sleeve, then terminate. I've had wiring all laid out then changed my mind quite often, so don't terminate until the end.

Nothing particularly difficult it's just a lot of the same sorta shit but repeated. Like a wiring diagram they look daunting, but it's just a lot of info packed into the one sheet.

I'm sure others are far more qualified than me and if KiwiRoy shows up listen to him above all!!!!!

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ignition switch on the T3

There is probably no reason to replace that switch, and end up with 2 keys. They are easy enough to take apart, clean the old hardened grease off that is holding the contacts apart, Scotch brite the brass pieces, apply fresh Vaseline, and reassemble. It is also FREE. (Guzzi content) :grin:

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Thank you very much, Weegie. That is incredibly helpful and gives me a much better of idea of how to approach this stuff. I was not aware of thinwall insulated cable, just basic copper wire. Really appreciate all of that great info.

Thank you, guys!

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My pleasure, I meant to add generally the terminals come in 3 sizes, you'll have seen the insulated type in red and blue, there is a third yellow.

Red is small, 1.5^2 nominal, I use for cable up to 2mm^2

Blue is med, 2.5^2 nominal, I use that for 2-3mm^2

Can't remember yellow but it's never used on motorcycles, for something like 3.5mm^2 which is never used, or I've never seen it on a bike.

The non insulated I think are the best, are usually sized according to CSA or AWG so easy to choose what you need

There's lots of other stuff out there too, but you usually need tools to use it and if it's a one off it's just not worth it. Neoprene (aka Hellerman) sleeve are great but heat shrink works just as well and doesn't need the tool.

For sleeving you have a few choices, take a look here for some choices


Solid PVC sleeve keeps the cables clean, but a bit fiddly when routing cabling in and out

I like the expandable netting type, as you can fish cables through it then use heat shrink on the end to tidy it.

Spiral wrap doesn't look as nice but you can take it off easily and fish cables in and out and it's easier to see damaged cable.

Anyway I need to go and get a life


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Thank you for that, John. You are a gentleman and scholar! And you’ve schooled me quite a bit here! Much appreciated. That’s great to know about the sizing, makes the system make more ease. 
Btw, what does ^2 mean?

I am away for the weekend and early next week, but will follow up when I am able to get into this next week.

Wishing all of you a great weekend!



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Hi Cliff

Sorry yeah difficult to communicate with a limited character set. The US generally use American Wire Gauge (AWG) sizing where here in Europe (if the UK is in Europe anymore?) generally tend to use conductor cross sectional area (CSA) usually in millimeteres square, that's what the mm^2 was meant to get across.

Lots of tables on the web going between AWG and CSA so it's easy enough to convert from one to the other.

Once you get to it perhaps PM me or just post up what you're planning and I'll see if I can help or have any ideas (I'm no expert)

I think I posted this up already (flagrant self promotion warning), but here was/is the Sfida 1000 just after I refreshed it a bit.

I custom rewired, the original loom was shockingly bad and hacked about (by me :blush: and others). Used an M-Unit (pricey) and Sasche PUREG (combined Reg/Rec and ignition system), little sections of the rewire can be seen in the vid.



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6 hours ago, Kane said:

That is some beautiful work! Wow. What’s going on with the alternator? And what exactly is a Sfida 1000?

Thank you but if I had to do it again, I'd do a few things differently, but (touches wood) the bike has been reliable and nothing has melted :rolleyes:

Just Google Magni to find out about the family and the bikes, based up near Milan, produce small numbers of bikes in their own custom frames. Their most succesful partnership was with Guzzi, who provided all the engines, transmissions, running gear and electrics and then placed them in their own frames and restyled the bikes to their own design, with an MV influence. Arturo Magni's history was as the race engineer for MV. Magni is best known for the parallelogram swinging arm, which elimates the shaft jack or crawl on the Tonti bikes. TBH you have to be really hammering them to notice any difference, but they do handle extremely well, considering the weight.


As Marty said that bike uses the LM 1000 running gear, I've added a few farkles and reduced its value, but I don't really care as I love to ride it, it's a lot of fun. There's a pic of the bike in the "Show us Yer Tontis" thread


As far as the alternator face in the video it's using a PUREG system developed by Volker Sachse https://www.elektronik-sachse.de/shopsystem-3/en/ his family I believe have kept the business running. Volker was killed in a motorcycle accident a good few years back and is sorely missed by me.

The PUREG is a Reg/Rec placed onto the face of the Bosch alternator and is slightly more efficient than the OEM offering. In addition the PUREG has the ignition system combined into it, that's the plate you can see spinning and the flashing LEDs. The trigger is an optical system using a wasted spark, the wasted spark occurs 360 degrees out of phase from when the cylinder needs a spark, so little chance of blowback into the carbs. There is a second box buried in the frame tubes, which controls the advance and contains circuitry for the ignition and coils. Its been very reliable and I've never required to retime it after initial setting, except once but that's because I was doing something else and had to remove the trigger.

Nuff about me, I only posted to show that a complete numpty can do it, it's not hard



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