Sort of a Work Case, but, well, it's worth a share. So, it's 2019 and three years after leaving the job I get a phone call from my old boss: "Hi Steve how's it going? Have I got a deal for you!"
It was a DRZ they were taking in part exchange. Of course, there was a catch, the bike had an electrical problem and wouldn’t start, so a low price agreed so even if the coils and whole ignition system needed replacing I would still have a good buy.
When the bike was dropped off I was quite happy - it was cosmetically very tidy, was the proper DRZ colour of yellow(!) and a 2007 model - my newest bike for some time!!
It did however have a lot of loose and cut wires where someone had tried, unsuccessfully, to fix it. So first job was to repair some of that, check for continuity and shorts, and basically start the fault-finding from scratch.Much to my surprise the bike then fired up instantly, sounded very smooth and there was no smoke – great!
Ooops, spoke to soon, as it stopped dead.
A quick probe around with the multi-meter showed the main fuse had blown and there was a short to earth from the battery positive. OK….so I start checking over the wiring, and after a few minutes the short disappeared!
Oh great one of those....
The wiring was all in good condition so I try wriggling and bending every bit with no luck, so re-start the bike and it would run for 20 seconds and then die again, the short coming back.
Hmm, tricky! So I disconnect everything apart from the bare minimum to run the engine, i.e. the CDI and coil, start it up - it runs for a few seconds and dies again.
Whaaaaatt??
OK so study the circuit diagram to see what else is on the positive circuit, but it turns out I have already disconnected everything connected to 12V.
Well, apart from the CDI. Oh?
Of course the short has now gone again, so start the bike, again, and as soon as it stops I quickly check the positive line going to the CDI, and yes it is that! – the CDI has an internal short!
OK, unusual, and not ideal, but at least the fault is now found, and, as it happens I have another bike being broken for spares so a replacement CDI is already to hand. So fit that and the bike starts up and stays running, sweet as a nut – fantastic!
Now, the story should be over at this point, but having an electronics background I like to have a good probe around with the meter to check the generator ac, rectifier, and battery are all ok, Starting at the @rse end, I pop the meter on the battery and holy sh!t! - I quickly stop the engine as the regulator is putting out over 17 volts!
Which more than likely cooked the CDI and was about to wreck the replacement too! But fortunately I switched off in time.
The pic shows bike is all sorted now, but.... there is part 2 to of this to come as it turned out this story of electric problems was, um, not actually over
We have plenty of those in the Ducati shop where I work 
