Kiwi_Roy

I have zero confidence in the Guzzi presses switch. if you crack the fitting going to one of the heads it will soon let you know if there is oil pressure or not. I suggest you add an oil pressure gauge, oil is normally ~ 60 psi Update I thought I had mentioned that the switch tracks across the dirty wet switch insulator, usually all it takes is a wipe with a rag or spray with CRC For most of my working life I designed industrial instrumentation, you don't buy anything and expect it to work reliably unless it makes sense, a pressure switch that works by distorting a tiny bit of metal a microscopic amount to make a contact makes no sense at all. An industrial switch would have a decent size diaphragm working a snap action switch however switches in an industrial setting are a pain in the arse, we would usually specify a pressure transmitter that could be trended and do the switching in a computerized control system.

I like that as you say you would be able to replace it until you have a chance to solder another in. I had one fuse weld in so I cleaned up the contacts and tightened the clips and it never re-occured. I always meant to look at the current with an oscilloscope, I'm sure the peaks must be well over 30.

I;m assuming you have one of the later VIIs with the Start relay powered from the Ignition Switch Typically there is too much resistance in the ignition switch and it's associated wires. The Starter solenoid has two coils one that pulls 10 Amps and another that would like to draw 40 Amps but just for a few milliseconds while the solenoid engages and the main contact closes, This is such a common problem it's been named "Startus Interruptus", common to almost every other Guzzi right up to the latest. You need to clean the ignition switch every few years, take the switch block off the lock (2 Phillips screws) and open it up, wipe out the old grease and replace it with fresh Petroleum Jelly aka Vaseline. There is a permanent fix (strong feed) that requires a direct connection to the start relay 30 terminal from the battery but it also requires a different arrangement for the feed to the headlight relay, try cleaning the switch first. Drop the negative wire off the battery to make it safe. I think your problem with cutting out is possibly a dirty side stand switch, carry a short length of wire to stuff in the relay (15) socket 30-87, this will bypass the stand switch as a test. Further reading https://www.v11lemans.com/forums/index.php?/topic/21206-startus-interuptus-revisited/

Why do you need to disconnect the wires? Chop the connector out and use a couple of crimp links or solder the wires. If you ever need to replace the wires make them a bit longer so if you ever need to chop them you have enough length to shorten them. Heat is resistance x current squared and I believe the current spikes are very high leading to lots of heat. Also i think the crimp connectors available in The America are smaller than the OEM Guzzi ones.

The 2000 will have 2 relays in series feeding the headlight, Start relay Normally closed and Headlight relay Normally open, the Voltage reference is tapped into the wire part way along the tank so its subject to the Voltage drop I mentioned. You will see this if you measure between battery Positive and the Black wire of the regulator The previous owner may have upgraded the regulator already. If it still has an ancient Ducati Energia regulator definitely add a ground strap from the regulator to an engine bolt and consider a method of eliminating the Voltage drop. On the other hand the starter wiring on these early models should never have a problem, the start relay is fed direct from a fuse. Clean the ignition switch, and change the side stand switch, this model can get very dirty before it starts to drop out the ECU Guzzi Wiring - Simple.pdf

I believe that happens because of the flakey Voltage reference downstream of the headlight relay. This is particularly bad on the earlier bikes where they had two relay contacts in series with the headlight current, The Voltage the regulator sees is normally about half a Volt lower than the battery Voltage but if the bike has been sitting for a while I have seen mine as much as 1 Volt lower. So when the regulator sees a Voltage 1 Volt lower it jacks up the charging to compensate and the charge current goes up exponentially which will overheat the diodes melting the leads off. My first experience with this I was able to remove the potting material and re-attach the leads to get about another year out of the regulator, I also took the opportunity to reverse engineer the circuit. Finally I decided to fit a direct connected regulator, this solved the charging problem however it did add a small residual current that would flatten the battery if left over the winter.

I suggested this quite a while ago Take a maxi fuse link and drill a hole in each blade then bolt lugs to it, that will ensure a low resistance and no heat.

My 2001 had the fuel come out the petcock on the LH side and returned to the tank on the RH through the pressure regulator so if you tilted the bike to the left the pump would immediately pump it back to the right. I took the pressure regulator off and inserted a bent tube in the return port to direct the return fuel over the hump to the left side. Idea being if you tilted the bike to get the fuel trapped on the right side it should stay left I sold the bike before I got around to testing the range I used hydraulic brake line it's available in several sizes

It may not be a relay problem, could be a dirty side stand switch allowing relay 4 to drop out resetting the ECU, try removing the stand relay R3 and stuffing a jumper in the socket between 30 and 87. This happened to my 01

The Start relay in this 2004 has terminal 30 fed from the ignition switch, I call this a weak supply. Look terminal 30 is so close to the battery on the drawing it's begging to be connected there. Chop the wire off and feed it with a direct fuse Also cut the wire off 87A and connect the two together so now when you press Start the light stays On and the engine leaps into life Turn the key Off and the light goes out If you decide you must have the lights turn off while cranking remove the headlight relay coil terminal 86 from chassis and run it to the starter, the second large terminal between main contact and the motor now while it is cranking the headlight relay coil will have 12 Volts on 85 and 86 so it will turn off. When the motor stops spinning it will turn back On because 86 is connected to chassis through the starter. Ther's more than one way to kill a cat, not just choking it with cream.

When I sketched this out it was not with Startus Interuptus in mind, it was merely to show how you can test most of the wiring from under the seat because all of the switches terminate at a fuse or relay contact. It was drawn from a 2001 VII Sport that never had a starting issue because Fuse 5 is fed directly from the battery. In Note 6 I had noticed something strange about the starter solenoid, by Ohms Law 12/0.3 should result in a current of 40 Amps, instead I measured 6 however this was after the inrush which was well over 30 Amps as I proved later when I discovered two coils in the solenoid. Getting back to Vuzzzi's modified sketch and GStallons extra relay, yes that will work for sure. The later bike will have the Start relay through the ignition switch so the original relay has a weak supply The fuse IMHO should be in the wire to 30 Having said all this you should still clean your ignition switch every 5 years or so otherwise it gets so bad it starts to cause the ECU to drop out

The OEM Ducati Energia didn't send Amps to ground, it just let the circuit go open circuit.

I thought this was worth posting here Jack of Roadstercycle warning to be careful you don't end up with a knockoff https://www.youtube.com/watch?v=TYxtCC330Xg

I thought this was worth posting here Jack of Roadstercycle warning to be careful you don't end up with a knockoff https://www.youtube.com/watch?v=TYxtCC330Xg

I thought this was worth posting here Careful you don't end up with a knockoff

With your new direct feed removing its largest load it shouldn't blow any more. With the old wiring as the switch got dirty the current dropped down to a point where it was taking too long to pull the solenoid in although I have no idea why it blew while running. If you look at the blown fuse it gives a clue, just a tiny gap indicates it was only mildly overloaded, a large gap indicates a short circuit. Fuse 4 also feeds Fuse 6 and 7 through the ignition switch.

You can also use a single LED with a pair of diodes to prevent cross talk, that's what I have on my loop. Here's a sketch I did for someone, In the first diagram I explain why its no problem with incandescent lamps The second diagram shows cross talk The third diagram shows how back to back diodes prevent cross talk, any small diode will do eg 1N4004. Note: All 12 Volt LEDs incorporate a series resistor to limit the current to 15 mA or less, I haven't shown these for simplicity.

The ignition switch is very easy to remove, just take a Phillips screwdriver and undo the two screws that hold the contact block to the lock (look up from below) Unclip the white plate and tilt it out. Need I say drop the battery negative off for safety. The switch also unplugs at the headstock if you want to do it on your bench. Note on this one how one wire had snapped off, the owner noticed the tail light had gone out. The wires were not fastened to the back of the switch cover, and they work hardened where they flex at the solder joint. The loom should flex evenly over it's length as you go from lock to lock, don't strap it down tight. Starter Solenoid Coils I can see your eyes starting to glaze over but this is what the starter solenoid is really like, it has two coils one that draws 10 Amps the other will draw 40+ but not with the modern wiring. (This was drawn from my 2001 VII Sport, the old Bosch starters are very similar) Nearly every bike Guzzi have pushed out the factory door will eventually suffer from Startus Interruptus all the new 1400s and miriads of V7s will fail as the CARC bikes are now and scores of owners will be turned off Guzzi all because they don't understand the problem. I have been preaching since 2012 without much impact. MPH in Houston will make a fortune selling their kits at $40 a pop, I don't begrudge them that. I have learnt to accept owners think because they pay for something it must be better than free advice LOL Cheers Roy

Locky, Look at the difference between the two diagrams around the start relay terminal 30, this one has 30 supplied directly from the battery via fuse 5 But this later bike has the start relay fed via the wimpy wires to the ignition switch and back Later is better right? Not so in this case, The former wiring has no trouble feeding 50 Amps to the starter solenoid, the Latter (weak) diagram would be lucky to get 30 on a good day, more likely 25 or Click Click AKA Startus Interruptus.. The factory screwed up, they never have to deal with a 10 year old bike with a failing ignition switch. How do you know which version you have? Pull the start relay out and measure with a Voltmeter or test light the 30 terminal of the socket to chassis (look at the layout on my sketch below) If it is 12 Volts with the key turned Off or On you have the good version If 30 is dead with the key Off you have the latter weak version As the bikes age the grease inside the switch goes hard and tends to hold the contacts apart increasing the contact resistance Pull the ignition switch apart and clean the old grease out, replace it with nice fresh Vaseline and it should crank ok for a few years OR Re-wire it like Chuck did his Scura and never have to worry about cranking again. (unless the magnets drop out of the Vaelio which they have been known to but not because of the wiring) An added bonus for re-wiring is the way the starter seems to work much better or at least it has no delay between button push and whir. I have actually measured the time difference, the former 1999 is 3 times as fast. To prove this take 3 feet of wire with a spade connector on one end, plug it onto the starter solenoid spade terminal and touch the other end on the battery. WARNING - make sure the bike is in neutral and for extra safety pull the clutch in or the bike will leap out of the garage LOL

The first diagram has the start relay supplied direct from the battery, it will deliver 40+ Amps to the starter relay each and every time. The second diagram feeds the juice through a fuse, all the way to the front of the bike through the wimpy switch and tiny wires then all the way back to the relay, it will be lucky to get 30 Amps to the starter relay, more likely low 20s. This is the sort of wiring all the modern Guzzis are fighting , MPH are selling their Startus Interruptus kits by the thousand, all it does is adds wiring to make it more like No 1 What neither of these drawings show you is the correct starter wiring, there are 2 coils inside the solenoid, one that draws 11 Amps at 12 Volts and the other that draws 48 Amps at 12 Volts When I say 40+ Amps I'm allowing for some Voltage drop. My first Guzzi was 2001 VII Sport was wired like the first one, I couldn't figure out what Startus Interuptus was all about until I took the time to measure the solenoid. The coil shown on Guzzi diagrams is the one that measures 1.05 Ohms, Measure your solenoid from the spade connector to chassis, see what you get. For a giggle Google "MPH Startus interuptus kit", makes me sad that Guzzi have been struggling with this for 40 years and are still pushing bikes out the door doomed to fail.

I think they leak through the sensor itself, in around one of the transitions between one material and another (steel to red epoxy or red epoxy to black case). Then it travels up the cable or out again between the cable and epoxy on the outside. Stick a condom on it, seriously, try glueing a disk of plastic right across the surface covering the tip. Don't stick a fat "O" ring on it, all that does is mess up the gap.

No, The headlight relay coil now has 12 Volts on one side from the ignition switch (it is no longer switched while cranking by the start relay) The other end of the coil is presently going to chassis, if you remove it from the chassis and connect it to the short jumper cable between the solenoid and the motor brush it will be grounded through the armature. While cranking it will be at 12 Volts, same as the ignition switch end so the headlight relay will drop out. This is kind of unusual wiring but it saves adding another relay just to switch the headlight off for a couple of seconds.

Make sure the Start relay terminal 30 is always alive, the cause of starting failure is usually because the factory wired the relay through the ignition switch. The factory don't show the coil that draws 40+ Amps. The wiring is not capable of supplying this current.

The only thing is now the headlight doesn't turn off while cranking, ~ 5 Amps, not a big drain when compared to the starter around 150 - 170 Amps. If you want to drop the headlight out take the ground off the headlight relay coil and run it to the starter between the main contacts and the motor. It will normally be grounded through the motor turning the lights On. When the starter is cranking the point between the main contacts and the armature will be at 12 Volts (both ends of the coil will be at 12 Volts) so the relay will drop out until you take your finger off the start button.

The Generator light is fed from headlight relay (14) 87 terminal which also supplies the oil light and several other loads including the Ducati Energy Voltage regulator (if you still have that) The headlight relay coil is fed from the 87A contact of the Start relay just above the starter (22) I think, Cut the wire off the 87A and feed it from the ignition switch (the wire that was originally on Start relay 30 if its still there)