S4 Lighting relay where is it ??? - Page 2

Albie · 08-08-2019, 06:08 PM

Quote:

Originally Posted by LVC

Well what a chuffing PITA that was ....

Good old Ducati had changed the wiring between my 2001 S4 and the Workshop manual I have for the 2002 S4 ..... and what had they changed ..... they have removed the stupidly, stupid capacitor/diode/piece of crap thingy that is hidden in the wiring loom on the side light circuit from the switch.

By pure luck I cut into the "bulky part" of the loom just behind the head stock to find than either side of a well hidden "lump" on the side light circuit I was getting no continuity ..... offending item bypassed as a test and all works ..... so now has been permanently removed and the two ends of the wire correctly connected and all is good again ..... you have got to love 18 year old dodgy italien electrics

For those interested here is the chuffing part that is dead and causing all the problems ....

Thanks all for your help - we got there in the end

There is no way that's factory fitted by the soldering for a start. Maybe he thought wiring poor standard in first place. Thought he knew better. I think not so.
Glad its sorted now.

Flip · 08-08-2019, 06:18 PM

Well diodes are usually there to protect something- in this case something behind the Anode (non banded) side.

So where does that wire go to on the Cathode side (banded) and back to on the Anode?

My worry would be that it is there to protect the switch from getting direct voltage to it if it is switching the ground.

Darren69 · 08-08-2019, 06:36 PM

I'm sure I have a pdf copy of the S4 '01 factory manual filed away somewhere, which I may be able to send you. Mine's an '02 and you're right they did make a few changes to the wiring as the ECU was slightly different from '02 on.

LVC · 08-08-2019, 06:40 PM

Quote:

Originally Posted by Albie

There is no way that's factory fitted by the soldering for a start. Maybe he thought wiring poor standard in first place. Thought he knew better. I think not so.
Glad its sorted now.

Yes it is pretty badly done - glad it's not OEM then I don't have to replace it

Quote:

Originally Posted by Flip

Well diodes are usually there to protect something- in this case something behind the Anode (non banded) side.

So where does that wire go to on the Cathode side (banded) and back to on the Anode?

My worry would be that it is there to protect the switch from getting direct voltage to it if it is switching the ground.

Yes i wondered that as I've LR90 that used to burn out it's headlight switch due to the current running through them but this is the sidelight circuit so really low powered anyway ... weird one

Downstream side is the switch connector and then handlebar switch itself, upstream I haven't investigated further as it's all covered.

It is however now a permanent live with the ignition on from the 15A fuse in the fuse box (marked for lights).

I can always fit another diode ..... what do you guys think ?

LVC · 08-08-2019, 06:42 PM

Quote:

Originally Posted by Darren69

I'm sure I have a pdf copy of the S4 '01 factory manual filed away somewhere, which I may be able to send you. Mine's an '02 and you're right they did make a few changes to the wiring as the ECU was slightly different from '02 on.

That would be most kind if possible ... Wetransfer is good for stuff like that and my email address is tony@wellsdomain.com

LVC · 08-08-2019, 07:10 PM

Now even more confused as I've just checked diode orientation and the cathode line is on the switch side of the diode .... which, unless I've got it wrong, means that the flow is from the fuse box towards the switch so the diode would only prevent a reverse flow back to the fuse box. So it wasn't/can't protect the switch from having a live current through it ?????

Flip · 08-08-2019, 08:37 PM

We need to know where that blue wire physically starts (the fuse-if so which one and is it the correct rating?)and finishes (side light bulb?) and what if anything it passes through (the switch?).

LVC · 08-08-2019, 08:50 PM

Quote:

Originally Posted by Flip

We need to know where that blue wire physically starts (the fuse-if so which one and is it the correct rating?)and finishes (side light bulb?) and what if anything it passes through (the switch?).

I assume it starts at the 15A lights/indicators fuse in the fuse box (as pulling this fuse stops the current through the blue wire) and I know it ends at the handlebar switch (pretty certain it's the sidelight circuit there as I was getting continuity on the main beam side but not sidelight side from the switch to the headlight connector until I bypassed the diode).

Note: Sidelight circuit has to be on first for the main beam to come on via the handlebar switch.

Darren69 · 09-08-2019, 09:20 AM

Quote:

Originally Posted by LVC

That would be most kind if possible ... Wetransfer is good for stuff like that and my email address is tony@wellsdomain.com

I just checked and it is the '02 one that I have not the '01, so same as the one you have. Sorry.

LVC · 09-08-2019, 09:37 AM

Quote:

Originally Posted by Darren69

I just checked and it is the '02 one that I have not the '01, so same as the one you have. Sorry.

No worries thanks for looking (I haven't been able to find one for a 2001 hence why I have the 2002 .... will keep looking)

Luddite · 09-08-2019, 10:29 AM

There's a 2001 S4 owners manual (91370601F - printed 01/2001) on issuu with a wiring diagram on page 78, which might help.

https://issuu.com/marcoslara5/docs/d...wner_s_manu/78

LVC · 09-08-2019, 10:44 AM

Quote:

Originally Posted by Luddite

There's a 2001 S4 owners manual (91370601F - printed 01/2001) on issuu with a wiring diagram on page 78, which might help.

https://issuu.com/marcoslara5/docs/d...wner_s_manu/78

Thank you, yes this confirms what I thought - fuse box to switch with no diode - still can't see why anyone added it though but won't be putting one back unless I discover a really good reason to.

350TSS · 09-08-2019, 09:40 PM

Could it be anything to do with an alarm system. The quality of the soldering /joining looks nearly as bad as the alarm system fitted to my ZX9R when i bought it second hand.

LVC · 09-08-2019, 09:51 PM

Quote:

Originally Posted by 350TSS

Could it be anything to do with an alarm system. The quality of the soldering /joining looks nearly as bad as the alarm system fitted to my ZX9R when i bought it second hand.

There isn't an alarm, just the factory immobilizer .... absolutely no idea why it was added

Luddite · 09-08-2019, 10:40 PM

Have a look at the thread Lucaz started on the Ducati Forum, particularly the picture in post #3.

https://www.ducatiforum.co.uk/thread...this-for.4933/

It's a diode to stop a voltage spike travelling back down the loom when the starter solenoid disengages. Does your bike have one in the same place? If not, I'm wondering if yours was moved, as some posts suggest Ducati relocated it further up the loom to protect it from damage.

08-08-2019, 06:18 PM	#17
Flip Registered User Join Date: Mar 2010 Location: Beachtown Bike: M900 Posts: 2,188	Well diodes are usually there to protect something- in this case something behind the Anode (non banded) side. So where does that wire go to on the Cathode side (banded) and back to on the Anode? My worry would be that it is there to protect the switch from getting direct voltage to it if it is switching the ground. __________________ You're perfect, yes, it's true- But without me you're only you!

08-08-2019, 06:36 PM	#18
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,022	I'm sure I have a pdf copy of the S4 '01 factory manual filed away somewhere, which I may be able to send you. Mine's an '02 and you're right they did make a few changes to the wiring as the ECU was slightly different from '02 on. __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

08-08-2019, 07:10 PM	#21
LVC The Loire Valley Monster Join Date: May 2006 Location: South of Le Mans Bike: S4 Posts: 709	Now even more confused as I've just checked diode orientation and the cathode line is on the switch side of the diode .... which, unless I've got it wrong, means that the flow is from the fuse box towards the switch so the diode would only prevent a reverse flow back to the fuse box. So it wasn't/can't protect the switch from having a live current through it ????? __________________ *Kiss French, Play Japanese, Ride Italian....*

08-08-2019, 08:37 PM	#22
Flip Registered User Join Date: Mar 2010 Location: Beachtown Bike: M900 Posts: 2,188	We need to know where that blue wire physically starts (the fuse-if so which one and is it the correct rating?)and finishes (side light bulb?) and what if anything it passes through (the switch?). __________________ You're perfect, yes, it's true- But without me you're only you!

09-08-2019, 10:29 AM	#26
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	There's a 2001 S4 owners manual (91370601F - printed 01/2001) on issuu with a wiring diagram on page 78, which might help. https://issuu.com/marcoslara5/docs/d...wner_s_manu/78

09-08-2019, 09:40 PM	#28
350TSS Too much time on my hands member Join Date: Jan 2013 Location: Shipbourne Bike: M900 Posts: 1,419	Could it be anything to do with an alarm system. The quality of the soldering /joining looks nearly as bad as the alarm system fitted to my ZX9R when i bought it second hand.

09-08-2019, 10:40 PM	#30
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Have a look at the thread Lucaz started on the Ducati Forum, particularly the picture in post #3. https://www.ducatiforum.co.uk/thread...this-for.4933/ It's a diode to stop a voltage spike travelling back down the loom when the starter solenoid disengages. Does your bike have one in the same place? If not, I'm wondering if yours was moved, as some posts suggest Ducati relocated it further up the loom to protect it from damage.