Starter Solenoids

[Kiwi_Roy]

It must be time I raised the subject of Guzzi starter solenoids again.
I feel like i'm fighting a losing battle over this (Startus Interuptus)
Just read over this sketch and ask questions if you have any.



An interesting exercise.
Take your multimeter and measure the solenoid spade connector to chassis.
Use Ohms law to calculate the current it will draw at 12 Volts.
Post your findings here.

[berniebee]

Ok, I'll bite. What is 2,880 AT and 14,400 AT?   

[Kiwi_Roy]

Ok, I'll bite. What is 2,880 AT and 14,400 AT?   

The magnetic strength of a coil is often expressed in Ampere-Turns, the current flow in Amps x the number of turns.
9.6 x 300 = 2,800 Ampere-Turns   48 x 300 = 14,400 Ampere-Turns
Magnetic strength is a lot more complicated than that but i'm just a simple sparky.

[RHAT]

I am skeered and ignorant about lecktricity and sparkle hoses.  I don't know what you said,  but I will be watching this thread in hopes of a more simple solution.
I am waiting now for a new starter.  A shop cleaned my original up, but no change.  I've installed the plug and play startus interruptus  with no change.  I don't know what else to do except try the new starter when it shows. 
Connections seem clean and tight,  battery is hot and test good under a load. I don't know what else to do other than throw new parts at it. 
2014 Norge 

[Kiwi_Roy]

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2014 Norge

PM sent.

[analog kid]

I feel like i'm fighting a losing battle over this (Startus Interuptus)

You are not....

This summer I used an old post and wiring diagram of yours to successfully troubleshoot and repair Startus Interruptus on my Mille. It was an intermittant fault too, making tx'ing even more fun!
IIRC, Guzziology was a bit of a help also, but does not go into nearly the detail you do.
I had not yet written to thank you,  and now's my chance!
I appreciate the time you took to write this up. I've printed off your wiring diagrams, which are now a permanent part of the motorcycle record. Thanks!

[old head]

I have fought startus interruptus for 10 years.

Finally, after 2 new batteries, replacing solenoid and cleaning starter, redoing all the connections, running wire directly to relay with larger wire to solenoid from relay, all of which helped but had not eliminated the problem.

Finally, started back checking all connections from solenoid back, and found the trigger wire loose that went to relay.  Since I fixed that, all has been good, no issues.  I believe in my case, it was a  multiple point issue, not one specific problem, but a combination of several issues that in combination or as a single point of weakness was the cause for no crank.

Notably, lithium battery has low voltage when cool, cables not as shiny as they should be, weak solenoid, low amperage to solenoid thru factory wiring.

since Nov, no issues for me, fingers crossed.

Old Head

[Chuck in Indiana]

I have a file on the computer titled, "Kiwi Roy's electrical stuff." Believe me, you are not typing in vain.. many have learned a lot about sparky stuff here, if they pay attention. Thanks again..

[Redrider]

The contacts spark at the beginning and end of the solenoid action, causing burn damage every time the button is used. I have fixed my solenoids several times with a good cleaning and lube but things will eventually deteriorate to non-functional.

[Wayne Orwig]

Roy, there is often a fuse near the battery, feeding the wiring to the ignition switch. More resistance in the line. You may want to show that in the drawing it you edit it.


So it is:
Battery, fuse, wimpy wire, dirty switch, more wimpy wire, second fuse, relay contact, even more wimpy wire, massive solenoid.

[Mackers]

...and found the trigger wire loose that went to relay.

That, too, was my issue on my '06 Breva.

[Kiwi_Roy]

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 loose a Volt and 10 Amps at the solenoid right there, a 16 gauge or 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. The 06 Griso comes with the start relay powered direct from the battery.

I do keep rabbiting on about how much current the solenoid draws, a typical Guzzi with the relay wired through the switch probably gets about 30 Amps on a good day but if the relay is wired direct it will get 50 Amps every time. This high current only lasts while the solenoid is stroking, as soon as the main contacts close it drops to ~10 Amps through the light coil while cranking.
Note I say 48 Amps at 12 Volts but with Voltage drop across the switch it could easily drop to 30 at 7.5 Volts you can easily measure the Voltage if you temporarily drop the main positive lead off to simulate the contact not closing, then the high current surge lasts as long as you hold the button, its hard to measure the current but it can be calculated from the Voltage at the spade connector / 0.25 (coil resistance).

Power is current squared x Resistance
Normal Guzzi solenoid 30 x 30 x 0.25 = 225 Watts
OR
Direct Guzzi solenoid  50 x 50 x 0.25 = 625 Watts
Which one is working harder?