Kiwi_Roy

It's not easy to measure the solenoid current you'll just have to trust me. I discovered that the solenoid has two coils one day when I was playing around with the 2001 VII Sport I had at the time. I put my meter on Ohms and measured the resistance from the solenoid spade to chassis, I was surprised to find less than 1 Ohm. That particular model VII has a direct feed to the start solenoid from the battery so it never suffered from Startus Interuptus, it would always crank. I did some further testing and found that the two coils measure 1.25 Ohms and 0.25 Ohms and will draw up to 60 Amps for a split second (you can calculate the current by simple Ohms Law 12 Volts / 1.25 Ohms = 9.6 Amps 12 Volts / 0.25 Ohms = 48 Amps for a total of 57.6 Amps (substitute a slightly higher Voltage and it 's well over 60) All Guzzis with electric starters have this double coil but if you look at any Guzzi schematic you will only see one, ask yourself could that be the reason the factory has never cured Startus Interuptus? If you look closely at the spade connector on the solenoid you should be able to see the two coil ends soldered to the terminal. I have pulled a solenoid apart and found each coil has around 300 turns of wire the reason there is such a difference in resistance, the lower resistance 0.25 Ohm uses a heavier gauge wire and it's wound on first so the wire is much shorter whereas the 1.25 Ohm coil is lighter gauge and the wire is much longer as its wound over the top. This heavy current only occurs if there is no resistance in series and it drops to just the 1.25 Ohm coil (~10 Amps) as soon as the solenoid contact closes 10 - 20 milliseconds after the start relay closes. On most bikes you will barely get 30 Amps through the ignition switch and spaghetti wiring so of course the solenoid is only pulling at half strength and waiting to fail. My apologies to Tesla, I will revert to something I learnt as an apprentice back in the 1970s The magnetic strength of an electrical coil is the product of the number of wire turns and the current flow expressed in Ampere-turns a unit not used very often these days . The 1.25 Ohm coil which I call the holding coil (because that's what it does) has 300 turns x 9.6 Amps = 2,880 Ampere Turns, that sounds like a lot until you calculate the other coil 300 x 48 = 14,400 Ampere Turns, so it's obviously doing the Lions share of the work, I call it the grunt coil because it does all its work in a split second, funny that the factory don't acknowledge this coil in their schematics. I'm sure some of you have had trouble with the 15 Amp fuse blowing, this happens as the resistance builds up so now the Grunt coil can't quite get the solenoid to move, it sits there drawing about 25 Amps for several seconds until the fuse pops. Why do the factory supply a 15 Amp fuse? my theory is they measure the solenoid current with a meter ~ 10 Amps, so a 15 would be appropriate, they completely miss the heavy current drawn by the Grunt coil because it happens so fast 15 - 30 milliseconds, too fast for the meter to catch. You can actually measure this peak current by disconnecting the main feed to the solenoid contact, then the high current will be there as long as the relay is closed. You probably think its just a simple circuit, the solenoid just pulls the starter in while the button is pressed but there's something interesting going on when you take your finger off the button, you no longer have power on the solenoid spade but the coils are still powered up via the closed main contact, now the coils are connected in series, current feeds back through the Grunt coil from the motor terminal to the spade terminal and so to the Holding coil to chassis. The thing is because its going backward through the Grunt coil and forward through the Holding coil and they both have 300 turns the fields cancel each other out so the solenoid lets go.

A couple of points. Yes there is normally a Voltage drop between the battery terminal and the Voltage reference of about 0.5 Volts due to the Voltage drop in the relay and socket etc. The OEM regulator is set low to allow for this, I think 13.8 from memory so when you add the 0.5 Volt it regulates at 14.3 (14.3 at the battery to get 13.8 at the reference point) The problem with this is as the relay socket resistance builds up I have seen over 1 Volt drop this can result in the regulator being overloaded as now the battery needs to reach 14.8 Volts Yes, adding headlight relays powered direct from the battery upsets the Voltage reference because you lose the Voltage drop. Yes, the Ducati Energia is a series regulator. it goes Open as the Voltage goes above set point whereas a shunt regulator shorts out the alternator when the battery is over set point. I don't know anything about the Oddessey battery, I thought it was just an AGM type.

P6X, That's very thoughtful but I have one question Since none of the Guzzi schematics show that there are two solenoid coils and the factory only provide a 15 Amp fuse to protect a circuit that can pull up to 60 Amps can you really say they were designed? I put it to you that the factory engineers don't know there are two coils and they measured the current at the solenoid spade terminal with a multimeter, 10 Amps so lets put a 15 Amp fuse to protect the circuit. I have measured 60 Amps there but only for a split second. If its not wired right the current is throttled and as a consequence the solenoid only develops a fraction of the pull its capable of and you get the dreaded click. I also see evidence of the factory thrashing around adding extra relays to try and solve the problem as for example in the later model Griso and Norge 1200s, if they would only draw the coils correctly a light bulb might turn on. Cheers Roy

I just came back from 6 weeks holiday, (central Nth island), unfortunately the computer I had wouldn't access this site. If you are still having a problem we should be able to sort it out fairly quickly. You should have been able to get the switch apart, as far as I know they are all the same, the root cause is probably dried out lube inside

The ECU drain is only microamps, the 525 regulator shouldn't draw anything from the OEM wiring because it's connected downstream of the headlight relay. The black wire acts as a Voltage reference but it also powers up the electronics.

A good idea But actually doesn't the 515 connect to the headlight circuit just as the original Ducati energy did? The headlight circuit already has the relay, I could put my VII Sport away at the end of summer and start right up again in the spring, no battery tender required.

From page 1 I couldn't figure out why the Tach had stopped but the headlight was still on (the tach is fed from the headlight relay), then I remembered perhaps you have after market headlight relays which bypass the OEM headlight relay.

This is the one I used, the ESR510, it completely eliminates the flakey Voltage reference. One thing to be aware of though it does draw a tiny current from the battery that will drain it down over the winter. You can eliminate this current by pulling the fuse over winter but you'd better remember to replace it in the spring, don't ask me how I know. Electrosport say,"Because many older Ducati's suffer from poor wire connections in the wiring harness we designed the ESR510 to have output wires that are connected directly to the battery terminals. The lead wires also have a 20A fuse inline for security" They also have a plug and pray model the ESR515 but I couldn't wait to get rid of the unreliable Voltage reference down from the headlight relay.

How about some BA9s from Superbright. https://www.superbrightleds.com/moreinfo/ba9s-ba7s/ba9s-led-bulb-5-smd-led-tower-ba9s-retrofit-car/2077/ Actually go through the whole bike and get LED replacements and make it worth the postage. https://www.superbrightleds.com/moreinfo/miniature-and-subminiature-bulbs/194-led-bulb-1-led-miniature-wedge-retrofit-car/197/ These are great for the dash buy all the colours to match the lens, the nice thing about the 194 is they are an AC lamp so you don't have to worry about polarity, they have a shoulder that fits into the white holder and you can solder the wires direct to the lamp because they should never need replacing. I use the 90 degree ones. For the direction indicators perhaps https://www.superbrightleds.com/moreinfo/bayonet-bulbs/67-led-bulb-15-led-forward-firing-cluster-ba15s-retrofit-car/169/ With an LED flasher- you can buy 2 pin ones but i'm more confident in the 3 pin variety with a ground conection. https://www.superbrightleds.com/moreinfo/flashers-load-resistors/cf13gl-02-led-bulb-electronic-flasher/782/836/ Head light bulbs are a bit of a crap shoot. I think they will be an H4, I currently run a fan type in my V7, I opened up a hole in the rear of the bucket to let it stick out, flush actually. You will find better deals by just googling. https://www.superbrightleds.com/moreinfo/led-headlight-bulbs-conversion-kits/h4-led-fanless-headlight-conversion-kit-with-internal-drivers-4000-lumensset/5321/11896/

If you don't have a Voltage reference to the regulator the regulator cannot turn the charging light ON and neither can it turn on the SCRs to charge the battery, Check the black wire of the black / white pair, should be 12 Volts with the ignition ON The Black wire plugs into the female of the M/FM pair, its Red/Black on the loom side, connects to the headlight circuit downstream of the headlight relay, its actually soldered to the headlight feed under the tank. The Male pin on the loom side goes to the charge light, the light will turn on if you ground that pin. The light gets +12 Volts from the same wire that powers up the Tachometer. There are quite a few variations on the wiring but this is always the case, if you are looking at the M/FM connector on the loom side the Female should show the battery Voltage when the key is On (without this the regulator cannot work) the Male should also show the battery Voltage but if you touch it to chassis the charge light will turn On. Make sure the regulator case is well grounded to the engine, don't rely on the black wire that goes all the way back to the battery, its just a token ground.

If the Tach stops working check to see if the headlight's off as well, the regulator gets its reference from the headlight feed after the headlight relay. If the reference is missing the regulator never turns on.

I used the drive to spin a magnet activated reed switch for a pulse input Speedhut.

You can see from the picture the bolt and spring clip do a very poor job of grounding the regulator, there's up to 30 Amps flowing between the painted metal bracket and the case, also I believe that bracket is bolted to the chassis with painted to painted surface, your beefy jumper wire at least has a fighting chance. I hope you used some form of corrosion inhibitor. I have in the past suggested that an aluminium strap could be used instead of copper wire cutting down on the number of different materials. I'm guessing you used an ESR515 which has no ground wire.

Another word against the small black wire guzzi provide, Some owners have experienced a poor connection on the main battery ground, in this case when you try to start the starter current tries to get back to the battery through the regulator ground turning it red hot which causes it to melt the insulation off other wires in the loom, I used to have a picture of that mess. On my 2001 the regulator was fitted to the horn bracket, nothing had been done to remove the paint from where the bracket contacted the chassis, A short wire from the regulator case to a timing cover screw takes care of all that..The other problem with the Ducti Energia regulator is it takes it's Voltage reference from the headlight circuit downstream of the headlight relay, that point can be anywhere from 0,6 to 1 Volt lower than the actual battery Voltage. Battery charge current vs Charging Voltage is some sort of exponential relationship so if you drop too much at the reference point you wind up with too much charge current and cook the regulator. IMHO you are much better to have a modern direct connect regulator even with its tiny leakage current. The modern V7s use a Chinese Shindengen regulator, I would use one of those before I bought another Ducati Energia. Look at Carl Allisons schematics on Greg Benders site, you will see the difference there.

He sent ne a set as well, What would we do without Pete?

No, the starter load is not carried through the ignition switch, just the solenoid load is. the starter motor itself will draw 150 - 170 Amps I don't believe the switch is rated at any more than about 10 Amps, I cannot find the specs. The solenoid has a massive job to do, it has to slide the gear all the way across to engage with the ring gear, I think it takes something like 30 Amps minimum to do that, but the solenoid is designed to pull 50 Amps so why not use all that power. Power = Current squared x resistance, the heavy current coil is 0.25 ohms At 30 Amps the power draw is 30 x 30 x 0.25 = 225 Watts At 50 Amps the power draw is 50 x 50 x 0.25 = 625 Watts Which do you think might work better? This high current to the solenoid only flows for a fraction of a second, as soon as it starts to crank the heavy coil is effectively switched out and the light coil just draws ~ 10 Amps I often see an owner say the bike cranks ok in warm weather but plays up when its cold, there's a very simple explanation for that. The ignition switch has sliding contacts and sliding contacts need to be lubricates or they will quickly wear away. When it is cold the lube becomes much stiffer than normal so it tends to take tension off the contact point therefore the resistance increases to a point that there is insufficient current flowing to get the solenoid moving 1/2 an Ohm is too much. Petroleum jelly aka Vaseline has been used for over 100 years to lubricate sliding contacts. As it ages the jelly loses some of the more volatile components this also makes it stiffer. I think if you were to clean and replace the lube in the switch every 4 or 5 years it would probably keep working ok but I recommend bypassing the switch altogether and give the solenoid the current it was designed to operate on i.e. 50 Amps. The easiest way to do this IMHO is to add another relay next to the solenoid using the original trigger wire to feed the new relays coil If you look at the schematic for a 1999 VII Sport you can see that the start relay on that model doesn't get its power through the ignition switch, instead it gets it from the battery through a fuse the one I had never hesitated to crank all the time I owned it. Another bike that got it right was the early CARC bikes, they also have a direct feed where later ones hav extra relays and still suffer.

Yesterday, October 6th 2021, the starter motor did not crank immediately upon pushing the switch. The Neutral and low oil pressure lights dimmed, so the current was drawn, but the starter only kicked in after about one second. This morning, the same situation happened, but it blew the 15 amps mains fuse. The battery is fine. I changed the fuse, and started the bike. Same issue without blowing the fuse. The starter motor did not crank right at the button push. The light intensity showed the current was drawn but the motor did not turn run away. It took about one second. Could be a sticky starter motor, or a going bad relay. Unfortunately, the OMRON G8HE-1C7T-R-DC12 DC12V does not seem to be available from a trusted seller. I found some on Amazon or eBay, but the sellers have warnings from "fakeguard". Anybody has any available for purchase? LMK Please excuse me if someone covered this already in the 7 pages I didn't read closely p6x, reading your original post it sounds like classic Startus Interruptus, not enough current getting to the starter solenoid. Possibly as the result of a dirty ignition switch, it could also be a relay or relay base resistance but my monies on the ignition switch. Pull it apart and wipe out the old grease replace with fresh Vaseline. The solenoid needs an inrush of about 30 Amps to goad it into motion so just a tiny amount of resistance and it falls in the 20 - 25 Amp range where it will cause the 15 Amp fuse to blow. The starter solenoid is designed to draw 50 Amps, its amazing how well it works when it's wired accordingly.

If you find the spade connector on the solenoid loose thats a sure sign it has been overheating due to resistance. The metal has annealed loosing tension. Replace the spade connector and don't forget to apply some Vaseline to the wire before you crimp it on. On many Guzzi's this wire from the relay to the solenoid is too small, you can easily lose a Volt and 10 Amps at the solenoid right there, a 16 gauge or metric equivalent is about right. On my 06 Griso I up-sized this wire one size, the time to engage the starter dropped from 50 milliseconds down to 15

Its probably not the solenoid, the wiring is not delivering enough current. You only hear the relay under the seat because the solenoid is not getting enough current to start it moving. (I should add the solenoid plunger could be stuck if its gummed up with grease, I just use a couple of drops of 3 in 1) Do the simple test of hot wiring the solenoid from the battery, if it's easier take the starter relay out and touch a wire from the 87 contact to the battery Positive. You don't need the key On to try that but do make sure the bike is in neutral. If it cranks with the jumper there is no reason for it not to crank when its wired right. You might find its harder to get started in cold weather, I put it to you that the grease inside the ignition switch is much stiffer holding the contacts apart, try flicking the switch back and forth a few times to see if it improves.. The real fix is to provide the start relay with a direct feed from the battery, not quite as easy on the Spine frame bikes because they use the normally closed start contact to power up the headlight relay, If you power up the 30 terminal the headlight will go when the key is off. There are several ways around this but i'm now in favour of adding another relay beside the solenoid triggered from the original trigger wire. The relay contacts go between the large positive post and the spade connector. A 20 Amp in-line fuse can be added between the positive post and relay terminal 30. p6x, its Startus Interuptus in this case (insufficient solenoid current) but when you clean the battery terminals don't forget the main ground at the gearbox and always use a little Vaseline to keep the contacts clean free from corrosion. Update, p6x, I suspect it's worse when cold because the grease inside the ignition switch is stiffer trending to hold more tension off the contacts, if you take the switch apart you will see this. Fresh Vaseline is much softer so it can flow out of the way, You could remove all the grease and leave it dry but then the contacts would vanish in no time flat. Electricians have been using Petroleum jelly aka Vaseline on sliding contacts for 100 years. Its not just your VII that suffers from this ailment, The Brevas large and small are well known for it, later 8 Valve CARC bikes, the earlier 4 Valve CARC bikes had direct wiring. The modern bikes like V7s don't seem to be suffering yet but I suspect that's just age, they all have a similar 2 coil solenoid wired through the switch. "Moto Guzzi, making Electricians out of riders since 1921."

The early VIIs like my 2001 Greeny had the start relay powered direct from the battery via fuse 5, (the start relay 30 terminal was always alive, it never had a problem cranking but then a couple of years later the factory changed the wiring so that the start relay is fed from the ignition switch via a switched fuse, thats when things went to hell in a handbasket. Pull out your start relay and see if the 30 terminal is alive with the key Off - Good Do you have to turn the key On - Bad MartyNZ said "I had these symptoms on my '03, after the bike sitting unused for too long with the rear drive out. I replaced the 5 pin relay in the forward position, and now all good. This time I binned the relay, instead of putting it in with all the spares of doubtful function in the monkey paw trap." Another problem with the VIIs the relay bases corrode or build up resistance between the pins and the socket, if you wiggle the relay in the socket it restores the connection somewhat, you can also remove the contacts from the base and squeeze each connector a little to improve the tension. I always applied a little Vaseline to my relay pins, there is probably something better. Typically the wire from the relay to the solenoid is too light a gauge, the factory don't size it for 50 Amps. Because the starter solenoid draws so much current while it is pulling the gear into mesh resistance between the battery and the solenoid is critical, 0.2 Ohms is right at the ragged edge. Calculate how much Voltage drop you will get at 50 Amps. Most other guzzles can be fixed by simply providing a new permanently On feed to the start relay however your VIIs use the normally closed start contact to power up the headlight relay so its a little tricky, lately I have been suggesting an additional relay to solve this problem. I can see some of you going "50 Amps, what's he smoking" so do a simple test, measure with your Ohmmeter from the spade connector to chassis (don't forget to subtract the lead resistance) Calculate 12 V / Resistance to get Amps. Ohmmeters are not particularly good for measuring low resistance but see what you get.

No, its not the solenoid, you are losing Voltage across the ignition switch and wiring, you can see it in the lights, there's not enough current to pull the battery down, its dropping across the resistance. I'm willing to bet if you took a jumper wire from the solenoid spade connector and touched it on battery Positive it would start every time no matter how cold. The starter solenoid is designed to draw 50+ Amps but its hampered by the switch and wiring. It's also possible the ignition switch has a higher resistance because the grease in it is cold, cleaning and replacing the grease with Vaseline would be a temporary fix.

When you press start does the starter clunk in then just refuse to turn i.e. can't generate enough torque. Try scraping the battery terminals and especially where the main ground connects to the gearbox. Measure the Voltage at the starter to chassis while its trying to turn, anything over 9.5 should spin it over. Or do you just get a quiet click from the relay? The lights going dim indicate low Voltage, possibly lost across the ignition switch., Measure the Voltage on the spade connector relative to chassis while you press start, if the starter is not cranking you should see 12 Volts. Keep in mind the solenoid is designed to draw 50 Amps while it engages the starter and it's not even turning yet. As Guzzi feed it through the ignition switch you are lucky to get even half the design current so why be surprised when it doesn't work? Finally try hot wiring the solenoid from the spade connector to the battery positive, thats how it is supposed to engage the starter, with a loud clunk. Thats the most direct way of operating the starter, if it doesn't engage and crank its a starter or battery problem (including bad connections) I posted a sketch here https://wildguzzi.com/forum/index.php?topic=113795.0

If you have any Guzzi that refuses to crank first of all clean and grease the battery terminals and the ground connection. Then test the battery and starter by hot wiring the starter solenoid direct to the battery, use a wire about 3 ft long with a spade connector on one end, touch the other end on battery positive (caution make sure its in neutral). You dont need the key On for this, you are just doing a crank test, if it cranks over you know that the battery and starter are both fine. If the engine cranks over with the hot wire but not via the normal starter circuit chances are you have Startus Interuptus. It's not so straight forward to fix on a VII Sport as the normally closed start relay contact feeds the headlight. An easy way around this is to add a relay fed direct from the battery or hot terminal of the solenoid with the contact feeding the solenoid. The new relay coil can be triggered by the existing solenoid trigger wire with a ground wire on the other coil terminal of course.

It's just the spacer for the bottom screw, stops you reefing on the screw until the glass breaks.

I always thought that was the case, my 2001 was that way but lately I have been helping an owner with an early VII Sport, his doesn't comply. It's also possible the ones sent to a different part of the world had a different loom. I have been dealing with a Stelvio owner in Europe, he sent me a schematic that is significantly different to the ones in Nth America. Thats why I'm trying to establish how the Start relay is wired up front. I think any with the direct wiring can be made to work without adding a relay