Electrics overhaul

[Welshguzzi]

Once I have access to my bike again (currently surrounded by Christmas stuff - artificial tree, boxes of decs etc) I'm planning on giving the loom the once-over to clean up contacts and check all earth connections. Couple of questions: where is the main earth that runs from the battery situated? And also, I installed an Electrex reg/rec which apparently has an internal fuse but I've seen talk on the forum about a 30 amp fuse from the battery - do I still need this? The Electrex is wired directly to the battery.

 

Cheers. And a very Happy New Year to you all!

[docc]

The main earth leaves the battery and follows the tube of the seat subframe down to attach to the top right of the gearbox inboard of the seat latch release. That and the terminal stack directly on the battery are the primary grounds (earths). Adding one from the regulator case to the timing chest is a must. I ran mine to the spine frame and one from there to the engine.

 

Others are more familiar with your regulator, but I recall one poster eliminated his 30 amp fuse and soldered the wires together. I ended up with a MAXI fuse in that location after repeated failures (charred, burned blades and melting, but not blown) of the standard ATC fuse, both in the factory fuse holder and in an external holder.

[luhbo]

Fuses are installed as fire insurance, to protect the harness, not the other electrical devices attached to the harness. An internal fuse cannot do this.

 

Hubert

[Zooter]

While you're at it,

Ha, finally someone has realized what I have been rabbiting on about is correct.

The grounding of the regulator is VERY important, All of the alternator current passes back through the ground.

Actually the regulator doesn't regulate the battery voltage, it regulates the voltage between it's case and the black wire to 14 Volts or thereabouts. If you have a poor ground at the regulator it's the battery that looses out (1/2 volt lost in the ground is 1/2 Volt less that the battery will charge too)

The two spring nuts are not good enough to provide a good ground, you have two dissimilar metals getting sprayed with water and road salt or whatever, that's just asking for electrolysis. For my ground I drilled a 1/4" hole through one of the fins and attached a wire with a bolt slathered in grease. The other end I connected to a timing cover bolt.

 

Charging Circuit.pdf

 

"Recently I have been seeing the red charging lamp flickering on while riding down the road" Looking at the regulator schematic I can see how a bad ground would do that.

 

It's interesting that your bike was running rough with a bad ground, I haven't quite figured that out but I had a similar experience when my ignition switch was making bad contact, the bike behaved as you describe, flicking the switch a couple of times seemed to cure it. I talked another guy who's lemans was running hairy into overhauling his switch, he was amazed at the improvement it made.

I haven't quite figured out why the switch contact effected the bike running so much because the ECU gets it's power through a relay, unless it was so bad the relay was dropping out.

I also have a theory that a bad ground can lead to the early demise of the Ducati Energia regulator.

That reminds me, too much voltage at the battery seems to cause the ECU to cut out, making the bike lurch, I think it must have an internal over voltage cut out to protect itself.

 

It's very easy to check the ignition switch contacts from under the seat.

Test Point Layout August 18 2010.pdf

Measure between the base of fuse 6 to the 30 contact of R3, it should be ~ 0.5 Ohms each time you turn the switch on. The grease inside the switch goes hard after a few years and it holds the contacts apart. Mine dropped from anywhere from 10 - 16 Ohms down to a consistent 0.5 after cleaning.

 

Raz's point about the injectors is a good one, also if you have a bad connection in the circuit not only does the ECU compensate for the low voltage but also the resistance may prevent the injector opening at all. Each injector is ~17 Ohms so it wants to pull 0.7 Amps

The coils are 0.7 Ohms so they will pull an instantaneous 17 Amps, the fuel pump also pulls a whack of current. From memory the current averages out about 9 Amps but the peaks are easily twice or 3 times that. Any resistance will have a huge impact.

 

Another thing to check is the state of the relay base contacts, a high resistance there R4, R5 or a bad contact at the fuses can effect the bike's running. Even R2 the headlight relay base will have some effect because that's where the regulators Black wire gets the battery voltage reference from, the same wire also powers the tacho so it playing up can point to a connection problem that may also cause over-charging.

 

Sorry about raving on here but I love a good electrical mystery. http://www.v11lemans.com/forums/public/style_emoticons/#EMO_DIR#/oldgit.gif

You don't have to be an electrician to own a Guzzi but it helps.

 

I'm glad your bike is running much better, I hope others will take note and do this simple ground strap addition.

[Kiwi_Roy]

If your regulator has two wires that connect to the battery (Positive & Negative) it may not need to be grounded. I would still have an in-line 30 Amp fuse next to the battery, it's cheap insurance.

[docc]

Zooter is The Search Monster

[Welshguzzi]

That would be in the positive lead to the battery......? (Sorry, I have electrics dyslexia :-()

[Welshguzzi]

Yes, I picked up on the importance of a good ground from the reg/rec - I check and clean them both frequently (why only have 1?)

[luhbo]

That would be in the positive lead to the battery......?..

 

Positively

[Scud]

The 30 amp fuse seems clear - once I determine which wire to put it on.  Shame too, because I just had the tank off and could have traced the wires easily then.

 

Just to confirm about the extra ground strap:  I should attach it between the points as shown by the blue wire in this picture?  Obviously, I would run the final wire more discretely... I might even screw it in...

 

 

 

Benefit of the fuse is fire insurance - got it.

And the benefits of the ground strap are that the bike is less likely to suffer from surging and poor charging?

 

 

[docc]

That'll work!      I like using zinc plated, flat braided copper with soldered connections (all cozy in heat shrink) to ward off breaks from vibration, especially in a wire that short between engine and frame.

 

Be sure to clean the paint off under the bolt head, maybe use a "star" washer for bite, and paste it all over with petroleum jelly.

 

 

That last part may be optional in Southern California . . .)

[Kiwi_Roy]

A good regulator ground is very important with the Ducati Energia because the charging current goes back to the alternator via the ground to regulator case.

The two internal SCRs are bolted to the case

 

However some of the after market regulators have a separate negative wire, there's nothing internal connected to the case so they would be just fine hanging loose

 

It's very important to inspect the main battery ground, if that works loose starting current will try to find it's way back to the battery by one of the small ground wires, like the one from regulator case letting out the magic smoke as happened here.

 

I have toyed with the idea of chopping off the OEM ground and just relying on the strap to chassis which would avoid this situation when the main ground comes loose but it might create a different problem, at least the tiny ground wire keeps the bike running.

 

Here's where I found mine, underneath the seat release lock (small screw), luckily I caught it in time.

 

I moved it to, a gearbox bolt, in plain view.

 

 

If ever you experience really weak starting suspect the main ground for sure.

[MikeDelta]

I've got the importance of an additional ground strap from the voltage regulator case to the engine and I'm plannining to put and additional strap on my 2002 V11 Le Mans. What is not so obvious to me is why to drill a hole on one finn instead of using the existing fixing bolt of the frame/case..

 

 

MikeDelta

[Kiwi_Roy]

MikeDelta,

                  The fixing screws on mine were almost stripped, it had those silly spring clips to the horn bracket that's why I drilled the fin The Horn bracket is bolted to the frame with no obvious attempt to make a good contact .

Since doing that I have done other Guzzis with just a lug under the mounting bolt.

 

Yes, just connect the strap to the nearest timing cover screw or another bolt on the engine.

The path back through the engine, gearbox and main battery ground is better than the small copper wire Luigi provided.

 

I thought about disconnecting Luigi's wire but I think it may provide some insurance in case the main ground works loose. Without a ground I see nothing to stop the +12 battery terminal reaching 60 Volts or more, for that reason it's also important to keep the terminals clean and greased.

You have probably read it's not a good idea to jump the bike from a car battery because of spikes, I think it's ok provided the bike battery is connected so it can suppress any Voltage spikes.

[MikeDelta]

Thanks Roy,

I'll check first the bolt if it could be a reliable spot , otherwise there is the finn option.

What about the gouge of the strap, how thin or heavy should be the wire for properly doing its role?

 

 

MikeDelta