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Im new to this, I have a 97 Ducati 900ss sp, Had it running , now it wont start, no click nothing, even when u put a jump box on it, anyone have any ideas, i was thinking starter or solenoid?
 

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The starter relay is on the right side of the frame. Reach around behind it and push the wires and make sure they're seated tightly. That's all my problem was.
 

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solenoid issues

A major bugbear with my duke at one point was its habit of allowing the small white plug of the solenoid to break contact, and ducati being ducati, the solenoid on the monster was in just about the worst place possible to allow the plug to be prodded, much less removed and reinserted. It caught me out 3 or 4 times before I rotated the solenoid 180 degrees fror easier access. Part of the reason for this at the time being that if all else failed, I could easily short the solenoid terminals with something conductive (usually a spanner) to at least get me started. I seem to remember junking my side stand cut out switch not long after this problem happened to me the last time as it also played up and prevented me starting the bike once too often. I developed a hatred for anything that could potentially interrupt the start circuit after these initial gremlins. These days, many jap bikes have stuff to prevent starting in gear, with the sidestand down, the clutch not pulled in, etc etc etc etc. Are we really all idiots, happily, after removing all the 'safety' aids that can potentially cause a similar starter problem, my ZX7R and the duke will both happily start with me safe in the knowledge that a non starter is easier to identify. Not trusting my neutral light for years makes me infinitely more careful than any electrical protection anyway.
 

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Ditto on the white two pronged plug in back of the solenoid. Zip tie that puppy in place, no more problems.
 

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funny about turning around the starter solenoid and ziptying the white connector in place. that's what the factory did on the FE's. definitely a known problem as well as the main fuse near the rightside of the battery.

i know it sounds stupid but i assume the run/kill swtich is in the correct position when starting? don't ask how i know =)
 

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Having the same problem with my 92 900SS. when I pushed the starter button, the dash lights dim slightly, so I know the button is doing something. Connections were tight and white plug is firmly seated. So, I tapped the metal housing several times with a small hammer and it started right up. Obviously solenoid is failing, so ordered a Yamaha part 21-2988 that is reputed to work great. Have not yet installed it.
 

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When you install it - if you need to modify the connectors (the Yamaha unit uses a pigtail with bullet connectors, not the plug like the Ducati), make sure you do NOT cut out the diode at the plug. It's there for a reason... To reduce back EMF from the solenoid.
If you do a search on this forum, it was discussed in a thread - longtime back.
 

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Oddly, as common as this replacement seems to be, the how to threads seem to have virtually disappeared. In a nutshell, it appears that the lead from the starter button goes to the same side as the big lead from the battery. Small lead going to small and big to big, naturally. Then, the other big connector goes to the negative or ground side of the battery and the other small lead goes to the small lead on the same side of the relay as the negative battery lead.

Does that sound right to everyone? I just made some small male bullet leads that plug into the stock white plug in the Duc harness. They are an extremely tight fit, so I think they will stay in place. This way, I am not disturbing the diode.

Frankly, it all looks pretty simple, but sometimes life is not like that!
 

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One last question. I would think that the solenoid will work with all the above wiring reversed. In effect, switch the red battery lead with the black battery lead and also switch the small leads. Is that correct? At the end of the day, it's just a switch controlling another switch and the diode is happy as long as it is always on the hot side of the circuit.
 

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not really sure i understand what you're talking about, but is the negative side of the battery really connected to the starter solenoid? if so the person who did that shouldn't touch it again and should be kept away from it at all times in the future.

starter circuit, in terms of the large, high current leads, is battery + to solenoid, solenoid to starter motor and engine case earth to battery -.
 

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Sorry, should have phrased that differently. The positive (red) battery lead connects directly to the starter solenoid. The small lead from the starter button is connected to that same side of the solenoid, obviously to a smaller connector. The black large lead is coming up from the starter circuit at the engine below. You are correct. black battery lead goes to earth at engine case. All large leads have been substantially upgraded. In fact, I used heavy arc welding cable, which has some nice flex to it.

It is correct that the lead from the starter button is on the positive side of the solenoid, isn't it?

Thanks for the input.
 

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yes, the starter solenoid is activated by a 12v input. although, it'd work just fine as an earth input as well, but then one side would always be seeing +12v and some might see that as an issue. but that is how the later ecu activated starter solenoids work - the ecu just earths one side of the activation.

i don't know that the orientation of activation wires would be important though as such. the connector can only go in one way on the original, but that's connector shape based.

it sounds like you're expecting the feed lead from the battery to be connected to the same "side" of the solenoid, if you look at it as either side of the symmetrical centreline? that's not a connection i would make, i'd expect that to be of no relevance. could be wrong. try it both ways if you're unsure, then you'll know.

this confusion is bought on by the fitment of the yamaha solenoid with the activation wiring loom coming out of it, instead of the push in connector? i have fitted them in the past, but don't recall thinking about orientation too much.
 

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The original solenoids seem to be very difficult to find in new condition. I'm wiring it all just like the original. My bike is a '92 900SS, so pretty low tech. Starter solenoid activation is old school button. Currently, the lead from the starter button is on the same "side" (based on solenoid centerline) that the positive (red) lead from the battery is on. This is meaning that each "side" has a large and small connector.

So, due to the diode in the circuit, I am assuming that is an important relationship. The wires from the Yamaha solenoid are the wrong connector. I have made my own bullet connectors that will plug directly into the Ducati harness. The nice thing about the new solenoid is it physically the exact size as the original, so it sits in the rubber mount perfectly.

Really appreciate your input. I'm pretty sure I know what is going on, but the diode complicates it a little.
 

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the diode is a wiring loom thing, it's not relevant to the solenoid as such.
Actually - it is. It's there to stop back EMF surges (from the solenoid actuation) popping other electronics.

See this post from Punch - https://www.ducati.ms/threads/620-sport-going-haywire-wont-crank-help.433729/post-4303529
Or this one from me... - https://www.ducati.ms/threads/starter-relay-coil-connections.325713/post-4781249

And this one goes into more detail - tech stuff linked in further down - https://www.ducati.ms/threads/diode-replacement.422986/post-4201553
 
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