Ducati Monster Forum

Moto Board => Tech => Topic started by: kawazar on May 04, 2009, 04:35:21 PM

Title: Starter Solenoid
Post by: kawazar on May 04, 2009, 04:35:21 PM
Is the starter relay that CA Cycleworks sells the same thing as a solenoid just listed as a different name? Also, is the Yamaha one a more reliable choice than the OEM one? I haven't replaced mine in over 3 years and 18k so I was going to replace it before it dies and keep the old one as a spare.
Title: Re: Starter Solenoid
Post by: erkishhorde on May 04, 2009, 04:43:48 PM
I don't know the answer to your question but you send CA-cycleworks an email they're really good and responding.  [thumbsup] It's almost closing time now though so I don't know if you'll get your answer before tomorrow.
Title: Re: Starter Solenoid
Post by: kawazar on May 04, 2009, 05:16:58 PM
Yeah, thats why I posted the question here, I assumed they were closed already.
Title: Re: Starter Solenoid
Post by: He Man on May 04, 2009, 05:19:52 PM
its the same one just different brand. i had one.
Title: Re: Starter Solenoid
Post by: kawazar on May 07, 2009, 03:55:29 PM
I just went to install my new solenoid. As I removed the old connector I noticed a resistor that goes from one wire to the other to bridge the connector. Should this be here? The connectors seem to be factory and the resistor is in some kind of shrink tubing.
Title: Re: Starter Solenoid
Post by: ScottRNelson on May 07, 2009, 04:14:08 PM
Somebody explained how the part you're talking about is a "relay" rather than a "solenoid", but I don't remember the full details.  Something about a solenoid moving more than just electrical contacts.

The Yamaha part sold by California Cycleworks is the same part as the original Ducati part except with different wires and connector.  The Yamaha part has a much better connector than the one used by Ducati, for some reason.

As long as you hook up the wires so that they go into the relay the same way, there isn't much else to be concerned about.
Title: Re: Starter Solenoid
Post by: ozs4 on May 08, 2009, 05:50:12 AM
Quote from: kawazar on May 07, 2009, 03:55:29 PM
I just went to install my new solenoid. As I removed the old connector I noticed a resistor that goes from one wire to the other to bridge the connector. Should this be here? The connectors seem to be factory and the resistor is in some kind of shrink tubing.

Its a diode and it needs to be there.
Title: Re: Starter Solenoid
Post by: kawazar on May 08, 2009, 07:17:55 AM
Thanks for the help. I put the diode in, it just looks a little suspect the way its placed there. I thought maybe someone used it to try and bypass something. Thanks again.
Title: Re: Starter Solenoid
Post by: Speeddog on May 08, 2009, 08:57:34 AM
Quote from: ScottRNelson on May 07, 2009, 04:14:08 PM
Somebody explained how the part you're talking about is a "relay" rather than a "solenoid", but I don't remember the full details.  Something about a solenoid moving more than just electrical contacts.
----------snip------------

True, it's a relay, rather than a solenoid, for the reason you have stated there.

Quote from: ozs4 on May 08, 2009, 05:50:12 AM
Its a diode and it needs to be there.

+1
Title: Re: Starter Solenoid
Post by: Drunken Monkey on May 08, 2009, 03:06:08 PM
Relays and solenoids are nearly identical in function. Solenoids are just considered "higher duty" than relays for various reasons.
Title: Re: Starter Solenoid
Post by: BMiller on May 19, 2012, 08:21:11 PM
Quote from: ozs4 on May 08, 2009, 05:50:12 AM
Its a diode and it needs to be there.

I know this is an old thread, but instead of making a new one I'll ask it here.  I'm replacing my solenoid and found the same "diode" and thought someone added it since it doesn't look factory.  What is its purpose?  I pulled off the sloppy shrink wrap that was on it and here she is:
(http://i1255.photobucket.com/albums/hh634/bmillervw/Ducati%20M900Sie/photo1-2.jpg)
Title: Re: Starter Solenoid
Post by: suzyj on May 20, 2012, 12:10:37 AM
The more correct name for the doodad on our bikes that switches the starter motor on is a contactor.

Things that energise starters are often (usually?) called solenoids, because in cars they often contain a mechanical element that drives the starter pinion into mesh with the flywheel.

Even when the solenoid portion is absent, people still refer to them as solenoids.  I don't care whether you call it a relay, contactor, or solenoid.  It's pretty obvious what it is.

The diode is connected across the coil on the contactor.  When the coil is switched off, it's inductance tries to keep current flowing, even though there's no longer continuity.  It does this by generating it's own voltage.  The diode safely shunts this current to +12V, ensuring the contactor doesn't blow the freckle out of the driver circuitry in your ecu, which was never, btw, designed for driving a starter contactor.

It's a kludge, that allows Ducati to not use a relay to drive the contactor.  In practice it ensures your ecu gets damaged if you connect the battery backwards.  Don't remove the diode, but also don't connect your battery backwards.
Title: Re: Starter Solenoid
Post by: Howie on May 20, 2012, 12:26:25 AM
That diode is part of the factory harness.  It is there to stop current from flowing back when power to the solenoid is cut off and on.

AFAIK, contactor is a British term, or maybe solenoid is just just wrong automotive terminology, like calling the capacitor in a breaker point ignition system a condenser.  Here in the US automotive people call it a solenoid because current flows through heavy contacts closed by a plunger verses a relay where a set of contact points are closed.
Title: Re: Starter Solenoid
Post by: Langanobob on May 21, 2012, 12:39:19 PM
Maybe it's a regional thing, but all my life I've heard solenoid pronounced "Sellanoid" as if it had an e in the first syllable.   I don't know if I've ever heard it pronounced as solenoid with an O.
Title: Re: Starter Solenoid
Post by: JoeP on May 31, 2012, 06:57:51 PM
Quote from: howie on May 20, 2012, 12:26:25 AM
That diode is part of the factory harness.  It is there to stop current from flowing back when power to the solenoid is cut off and on.

Anyone know the spec for this diode? I broke it trying to change the connectors to the solenoid.  [bang]  [laugh]  [drink]
Title: Re: Starter Solenoid
Post by: suzyj on May 31, 2012, 08:07:06 PM
1N4007.

Common as muck 1A rectifier diode.
Title: Re: Starter Solenoid
Post by: JoeP on May 31, 2012, 08:46:14 PM
Quote from: suzyj on May 31, 2012, 08:07:06 PM
1N4007.

Common as muck 1A rectifier diode.

Thanks! Glad I won't have to carry around that 11 mm spanner much longer.  ;)