Kiwi_Roy

AC/DC clip meters are a fairly recent innovation, we have had AC ones for eons, but they won't measure DC, I haven't seen one that cheap yet. However multimeters with a DC millivolt range have been around forever almost. Heres how you can make a simple shunt, a #12 option will easily measure 200 Amps drawn by a Guzzi starter https://ibb.co/3kkcX7P If you live where cable sizes are in metric you will have to figure out the meter spacing, its very easy to do. 1, Take a length of wire, a meter or more. 2, Bare a spot near each end, these are where your meter will connect. 3, Pass a known current through the wire from each end (outside the two bare spots, measure the Millivolts 4, From the known current and millivolts you can calculate the distance between tapping points you need to get 1 millivolt per Amp Note: If you don't have a meter with Amp range you can use a high Wattage lamp on 12 Volts to give a fairly close approximation. e.g. 60 Watt headlight bulb 60 / 12 = 5 Amps, your meter should read 5 Millivolts. You must not connect your meter at the same point you connect the current you are trying to measure, the joint has a much higher resistance than the length of conductor, your meter would read too high.

Probably the ground to the ECU, This will fry pretty quick if you try disconnecting the battery terminals in the wrong order then accidental let your wrench touch the ECU Always disconnect the negative terminal first, reconnect it last that way there is no return path to fry little wires,

John asked me to look in on this thread, I used to know quite a bit about these systems. Firstly the alternator wires can be a problem, they snap off where they solder to the coils. When this happened to mine the copper was so corroded it was not possible to re-solder them so time for some new wires, its quite easy to solder the new copper to the coils. The bullet connectors where the regulator plugs into the stator leads often overheat, if this is a problem just chop the bullet connectors off and join to the alternator with crimp links or a solder joint. Grounding the regulator is critical, all the charging current travels back from the chassis to the regulator case so it can return to the alternator through the other yellow wire. The factory supply a small black wire from the case all the way to battery negative but this is far too small for the current involved. Run a short wire from the regulator case to a timing cover screw, the engine and battery main ground are massive compared to the tiny black wire. The regulator has a rectifier set up as a bridge, 2 diodes and 2 Silicon Controlled Rectifiers. The rectifiers sometimes go open circuit, this situation is very easy to set for if you have a meter with the diode test function, The diodes are connected from each yellow wire to the red wire, it should show about 0.5 Volt, since the diodes are between each yellow wire and the red pair its possible to add a diode on the outside. The way they measure the battery Voltage is very poor, it taps off the feed to the headlight after the headlight relay and in some cases a normally closed contact of the start relay. The relay contact and socket resistance changes with time, the Voltage drop can be anything from 0.6 to 1 Volt, I have a theory that the reference voltage drop approaches 1 Voltmeaning the battery Voltage has to be pushed above 15 to supply the regulator reference, this high Voltage demands more current which overheats the diodes unit the leads melt off. A warning sign can be the headlight out or the tachometer not working, chances are the battery is not charging and of course the charge light also fed from the headlight relay won't be working either fooling you into thinking everything is ok. I often thought of getting the Voltage reference from a different source downstream of the ignition switch, off one of the ECU relays or from a dedicated relay direct from the battery. This would give the regulator a lower Voltage reference because it expects a drop through the relay but it could easily be compensated for with some resistance ora diode in series. I struggled with this flakey Voltage reference for years then I upgraded to a permanently connected regulator from Electrosport, there was one minor drawback a parasitic drain on the battery, I used to disconnect the regulator over the winter but if you don't remember to re-connect it next thing you know the bike dies with a flat battery. Electrosport recommend their ESR515, I dont agree, it still relies on the flakey Voltage reference and a good ground connection. I used the ESR510 it is wired direct to the battery and it has a dedicated ground wire I don't think it supports the charge light. Instead of a charge light I recommend just purchase a battery Voltmeter for ~ $15 and hook it downstream of the ignition switch this will leave you in no doubt. https://www.amazon.com/12V-Voltmeter-Color-Digital-Display/dp/B07HHTZ1L5/ref=sr_1_46?dchild=1&keywords=12+volt+battery+meter&qid=1633586264&sr=8-46

Any $10 multimeter with a millivolt range can measure the starter current if you make a shunt for it.

Hi Jim, Unfortunately if you run a direct feed to the start relay of this bike it results in the lights coming On with the key off as you describe because 87A is alive with the key Off. Most other Guzzi models use a 4 pin start relay or leave the 5th pin un-used. There are a couple of ways around this 1) Restoring the original 30 feed from the ignition switch and adding an extra relay triggered by the existing trigger wire to the solenoid, this seems to be the way you are leaning at the moment. I would put that relay down by the starter and feed it's 30 contact with a 20 Amp fuse from the large solenoid hot terminal. The nice thing about this method is you don't really need to alter the original loom, the wimpy feed and tiny wires are perfectly adequate to supply the new relay coil. 2) Supply a direct feed to 30 (as you did) but clip the wire off the Start relay 87A contact and re-direct it to the wire you clipped off the Start relay 30 so now the ignition switch turns on the headlight relay directly (but now the headlight doesn't switch off while cranking). To get around this cut the ground off the Headlight relay coil and extend it down to the large terminal of the starter solenoid, not the live one but the one that goes to the starter motor. Now while the motor is cranking both coil terminals of the headlight relay are at 12 Volts so the relay drops out, when not cranking the relay coil is grounded through the starter motor. I'm not sure why you cannot get the ignition switch apart, First of all you only remove the two Phillips screws underneath the steering head to let just the contact block drop off leaving the lock in place. Tilt out the white contact plate by releasing the odd clip of the switch barrel. Drop off the battery Negative to make it safe or unplug it at the headstock. Putting it back, fasten the switch wires to the rear cover so the wires don't bend and snap where they are soldered to the switch plate. BTW A dirty ignition switch is often the prime reason for "Startus Interuptus", the Starter solenoid can draw up to 50 Amps for the split second while the gear is engaging, there are two coils in the solenoid not just the one the factory show, the Guzzi wiring and weak ignition switch chokes the solenoid through wimpy wiring to less than 30 Amps so it performs badly. With a direct feed the starter will engage 2-3 x faster.

Sounds like the ECU relay is not getting a signal to turn On See how Fuse 8 has 12Volts on it when the key is turned On If your bike is a later one without an electric petcock you can measure the Voltage at the ECU relay base and chassis Possibly the side stand relay. Check you have the right polarity on the battery, if that's wrong the ECU relay won't pull in but the starter will still crank.

What does the John Deere have to do with anything?

As Docc says I would suspect the ignition switch, when's the last time you cleaned the contacts? If you wire a small lamp to the petcock fuse F8 you may see it go dim or flicker confirming that there is a bad contact somewhere between the ignition switch, kill switch or side stand relay.

Voldav, this should be the schematic for your bike, click on it to zoom in. Fuses 1, 2, 3, 4 & 5 should be alive in respect of the chassis with the key Off, find a good shiny bolt and attach the negative meter lead to it. When you turn the key On F6 & F7 will also be alive, F8 becomes alive when the bike is ready to start. If you don't find this touch the positive meter lead to the battery Negative terminal that will become negative if you have a bad ground. I will check back in a day or so,

Solid wire like that has no place on a motorcycle and please use lugs On a high milage bike you may find the wires are starting to break around the headstock, if you can separator them reef on each wire one at a time, the broken ones will stretch and break. You can run a short wire from the headlight and ground it to the frame or an engine bolt to bypass the long black wire back to the battery, dont pass any current through the steering bearings.

Some of the Electrosports are a direct replacement so they suffer from the same flakey Voltage reference. Which model did you buy?

I find the easiest way to gap the sensor is to stick something like a glob of JB Weld on the tip, bolt it in place, wait for the JBW to set up then remove it again and measure the blob with a pair of callipers.

Are you also posting on Wild Guzzi that would improve your chances, all the Guzzis back then used the same sensor If not a member on there somehow send your cell No so we can link you up.

So the fuel pump is running but just for a couple of seconds? Is it still running while cranking over, if not it's probably the Phase sensor. The phase sensor turns on the injection relay through the ECU, the injection relay turns on the pump and the ignition coils, if the Phase sensor dies you lose the injection relay, pump, spark & injectors. You could make sure no-ones added extra spacers to the sensor, sometimes that gets done in an attempt to make it oil tight. The gap should be 0.6 - 1.2mm. Probably your best bet to find another sensor is to borrow one from a local Guzzi owner.

As Tomchi said, here's the schematic, the sensor has a short cable plugged in under the tank somewhere, measure between 1 & 2. Note also how the petcock fuse is right on the critical path battery to ECU relay, if you hot wire to fuse 8 it will also energize the ECU relay, the ECU will energize the injection relay. Actually that's a good point, does the fuel pump run when you turn the key On, if not it's something missing in the main interlock circuit. The pump will still run even if the Phase sensor has failed but only for a couple of seconds, if the pumps not running for the initial 2 seconds chinches are the Phase sensor is OK. (its a while since I looked at an old guzzi wiring LOL) When you turn the key On the pump runs independent of the sensor but only for a couple of seconds. When you crank the motor the sensor lets the ECU know and it turns the pump back On Actually for the starter to work, ignition switch, Sidestand relay and kill switch all have to be closed, that feeds the Start button.

It might well be the phase sensor others have suggested but it could be just a simple electrical fault. I would hot wire from the battery to the ECU, that will tell you one way or the other. The phase sensor is a very simple device, just a coil wound over a small magnet but it's absolutely vital, a good idea to carry one on a trip because there isn't work around that I know of. Sorry I don't seem to be able to post a link here but basically you need to be able to liven up fuse 8, the petcock fuse, that will back feed the ECU relay and so turn on the ECU. Be warned this will bypass the ignition switch, side stand switch and kill switch but that beats being stuck on the road. An alternative is reading the Voltage at fuse 8 with the key On, it should be alive, if not it's one of the 3 switches I listed above. I had a light on fuse 8, Docc named it the Go Winkie light.

Those brackets are super strong, i used to pick up the rear of the bike by the brackets.

It doesn't come on a stick like the VII ones but I'm fairly sure its value is the same, it would certainly work with an in tank fuel pump. You could adapt the V7 one by carving open the stick to access the connections. I would try to avoid having to re-make the tank seal.

The sensor is a thermistor, no capacitance at all just resistance that changes with temperature, yours read 1.4k because it was reasonably warm then you dipped it in fuel and cooled it down. I just went through this again with a V7 owner, he took the regular speedo off snd wanted to use a 12 Volt LED in its place. He tried using the LED directly with his sensor but of course found it was always lit. I tried to talk him into using an incandescent like the VIIs use but he wasn't having it Measuring the sensor on my V7 the thermistor is ~1,800 Ohms when cold (it will vary slightly depending on your fuel temperature) When the fuel drops below the sensor the V7 sensor starts to warm slowly until it's only around 90 Ohms. You have to be really careful not to supply too much current as the sensor will just keep getting hotter and hotter until it fuses in a puff of smoke, the small lamp that the VII comes with is nicely balanced for the sensor, as the current goes up it lights and the current falls back. The V7 dash does a similar thing electronically, it limits the current to 75 milliamps. I worked out that 150 Ohms was a good value to use in series with the sensor, it will pass enough current to warm it up but not enough to fuse it, the 12 Volt LED is wired in parallel with the resistor, it doesn't draw anything when the sensor is cold but is reasonably bright when the sensor warms up

Steve, Do you have the part No of that lamp, I bought one for my old Eldorado but couldn't find it again when it came time to do the griso. I ended up adding a pair of white LEDs

As for running LEDs in the indicators you will need a different flasher unit, the OEM flasher operated on lamp current. The current would heat up a bi-metal strip which would bend so the contact sprung open then cool down to close and repeat the process. The only way to make this flasher work with LEDs is by adding huge resistors to take the place of the incandescent lamp load, this is too crude. With LEDs you need a flasher unit that will open and close at zero current, these flashers normally have a third wire connected to chassis. Then you need to re-wire the idiot light, it came from the factory connected between Left and Right indicators the current drawn was insignificant compared to the incandescent lamps in the indicators, about 100 mA but with LEDs that tiny current is many times what the LEDs draw. All you need to do is wire a small diode from each side pointing at the idiot lamp with the other side of the lamp to chassis. The diodes prevent the lamp signal getting from Left to Right indicators, even if you change the idiot light for an LED you will need the diodes. This change takes place inside the dash, no additional wires except the new ground for the lamp. If you decide to change out the incandescents in the dash for LEDs don't even think about using the original lamp holders. BTW, if any of you also have a CARC Guzzi you do need to add a shunt resistor (just a tiny 1K 1/4 Watt) to some LEDs to keep the lamp alarm happy and stop the lamps glowing with the key off. I tried to add a sketch file but it's even too large at only 200 dpi

I like Footgoose's tail tidy, I made something similar for my Griso using the original tail-light but added some white LEDs to illuminate the plate. I just made mine of aluminium, much easier to work than stainless and holds a high polish. I think you need a rear hugger before adding the tail-tidy.

One cause of slow cranking is a bad ground connection. If the ground is not making good contact the return current from the starter finds its way back to the battery via the small ground wire from the Voltage regulator. Too much of this and the wire becomes red hot melting through and shorting to other wires in the loom. Make sure the main ground is connected to a gearbox bolt and not just the seat release lock. The battery terminals should be cleaned and protected with Vaseline. Measure the Voltage across the starter terminals while cranking (should be at least 10V) Battery Positive to Starter Positive (the battery terminal not the wire lug) (<1V) Battery Negative to chassis (as above) (<0.5V) Battery Positive to Negative while cranking (should be at least 10V) Of course the LiPo batteries are known for weak output when cold.

I used Helicoils on my VII Sport tappet covers, most of the holes are not blind, They make a job that's better than original.

I've forgotten but isn't the steering stem on the V7 hollow? Just use a piece of rubber hose with a bolt to squeeze it from the end to expand into the stem. No need to make it round if its hex at the moment.