It's dead, Jim.

[swooshdave]

Well, I got three rides out of the bike. I guess that's good. After looking at the wiring it seems like no small miracle.




The good news is the podtronics looks newer (as in non-stock). The bad news is that everything else looks original.

Turning on the ignition and no power, dead. Turning the key to "parking" and the tail light comes on.

I did the test on the engine stop unit (ironic term) and I think it's bad. I pulled the two green wires and still dead. Reading the service manual makes my head hurt. I suppose if I read Italian it might be better but the English translation is painful.

Is anyone making the engine stop thing? Isn't it just a resistor and a couple diodes? I've got breadboard...

Should I just plan on ripping out the whole harness and rewiring? The harness has been hacked on and is wrapped with a lot of electrical tape. Plus that fuse box would make baby Jesus cry.

[Steve Foster]

They used to call Lucas the Prince of Darkness - obviously hadn't seen the wiring of a '70s bevel. And to think that the Italians invented the wireless (Marconi was also from Bologna) and that the Ducati brothers started the company by making electrical components ....
When it comes to the wiring of my bike it's the single thing that poses the greatest dilemma about whether to keep it as original as possible and put up with it, or to let common sense rule and rewire the whole thing.
Good luck.
Steve.

[wdietz186]

Dave, It is in your best interest to toss the harness and start over.There is a good basic diagram here on the Bev Hev site. With the green wires off the transducers it should run as the ign. is purported to be self generating. The later engine stop device was a double pole relay and it just grounds the green terminals on the transducer. Failure is almost guaranteed with the Ducati Elettronica system so be ready, and a modern system will need a different wiring arrangement so you my want to see if it is sparking. The charging system might be [if early 860] the 750 style 150 watt alternator and a better rotor will boost the output enough to allow use of lights etc.

[swooshdave]

They used to call Lucas the Prince of Darkness - obviously hadn't seen the wiring of a '70s bevel. And to think that the Italians invented the wireless (Marconi was also from Bologna) and that the Ducati brothers started the company by making electrical components ....
When it comes to the wiring of my bike it's the single thing that poses the greatest dilemma about whether to keep it as original as possible and put up with it, or to let common sense rule and rewire the whole thing.
Good luck.
Steve.

I've been joking lately that the Italian electrics make ol' Joe Lucas look like Tesla.


From the workshop manual I found this. I assume since I have the earlier engine stop system it's a pre-May 1975 model. But I haven't seen it referenced before that you should connect the two green wires together.



I re-wrired my Norton from scratch with just a wiring diagram I created, I didn't even have an old harness to reference. The Ducati should be a piece of cake. :wah"

[abmartin]

I re-wrired my Norton from scratch with just a wiring diagram I created, I didn't even have an old harness to reference. The Ducati should be a piece of cake. :wah"

The job will be easier when you identify the components correctly. What you have called the engine stop relay is really the 12V flash relay. The engine stop relay is beside it. Based on the diagram on my 860GT factory workshop manual the wiring seems to be pretty much correct for your bike. The factory recommended replacing the early type engine stop relay with an improved version because of water-related issues. I remember doing this on my early 860GT as well as installing a more powerful alternator and improved regulator as recommended in the manual. 860GTs can be run without the battery, early ones with no modifications, later ones with the green wires disconnected from the engine stop relay. No electrical devices hould be used when running without the battery, including lights, horn, flashers etc.

There is also a recommended wiring modification to forestall destroying the regulator should there be a break in the charging circuit. Since you have an aftermarket regulator this may not apply to you.

I did change the fusebox to a better system with my bike as they are a weak point. Yours is the original. Another common modification was to substitute Japanese handlebar switches for the stock ones- I believe Suzuki controls were often used.

I would get the bike running again with all the electrical equipment working properly before re-wiring the bike from scratch.

Bruce

[swooshdave]

Good news. I was out checking the battery status and decided to flip the key on and off. Lo and behold I get the tail light in the ignition on position. Try it again and no. Dead. Wiggle the wires behind the ignition switch and the tail light comes on. Dead unreliably. Need to unwrap the sixteen miles of electrical tape the PO has around the wires and see what's what.



So the thing to the left (in the pic) is a relay for the turn signals? Interdasting.

I think a new fuse box is at the top of the list now, well, right after sorting out the short in the ignition switch.

[jumpjg]

Dave,

The flash relay is a headlight flasher relay. When a momentary button on the handlebar switch is depressed it will turn on the headlight, I suppose to be used as a passing warning. My '70 Fastback had a button like that on a Wipac switch.

The device you have labeled as a horn relay is part of a "city/country horn" circuit (I believe - had one on my late '74 Sport). Never understood how it worked.

Joe in St Louis

[swooshdave]

Dave,

The flash relay is a headlight flasher relay. When a momentary button on the handlebar switch is depressed it will turn on the headlight, I suppose to be used as a passing warning. My '70 Fastback had a button like that on a Wipac switch.

The device you have labeled as a horn relay is part of a "city/country horn" circuit (I believe - had one on my late '74 Sport). Never understood how it worked.

Joe in St Louis

Ah, high beam relay. Got it. It's like an archeological dig.

[Craig in France]

Hi Dave,

No more photos of that fuse box, please! I'm already gonna have nightmares for a week at least. Same as the one I had on my 860GT(E), all of 30 years ago now. Absolutely 'Designed to Fail'. Replaced it pdq with a standard auto parts one ...

Otherwise, the electrics were ok. Ah, no, they weren't. The switches leaked whenever it rained ...

Ciao

Craig

[swooshdave]

Tried to ride it today, made it a few blocks before coming back. I don't think I cured the air leak with my trailer park fix. Maybe I'll fix it correctly this time.