A little help needed..

[Chuck]

Needless to say, that did it. Thanks again, Roy.. I don't know what the Guzzi Community would do without you..

[Kiwi_Roy]

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.

[Chuck]

Quote

run it to the starter between the main contacts and the motor.

I'm not going to do it, but I'm trying to understand. Would that be pin 87 of the start relay?

[gstallons]

9 hours ago, Kiwi_Roy said:

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.

This is the way a load shedding relay on BMWs work . 

[Kiwi_Roy]

On 8/9/2019 at 3:31 AM, Chuck said:

I'm not going to do it, but I'm trying to understand. Would that be pin 87 of the start relay?

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.

 

[Chuck]

Thanks, Roy.. I understand now.

[Kiwi_Roy]

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