Tell me more about S4RS indicators

[jezzamondo]

Just picking up on old threads to work out how to replace all the indicators with LEDs in my S4RS. I'm pretty confused by posts covering replacement relays, multiple & single resistors in series or parallel wired across the bulbs individually, or across the flasher unit (YIKES!) Can anyone tell me if my S4RS doesn't then have a replaceable relay (it doesn't, right?), where's best to fit what size resistor(s)? Is there an accessible common return just to fit one resistor? (NB. I don't know if this complicates things, but my alarm flashes indicators together also.)

[Nickj]

As far as I know you have to either fit a relay designed to cope with the lower resistance of the LEDs or fit an in-line resistor on the + feed to each of the indicators. though it could go on the earth side in which case just the one would do as long as you take the earths from both sides out to a common point. This would probably mean changing the wiring even more.

These resistors are pretending to be standards bulbs, adding the resistance you'd get from one, so will get as warm as bulb would. The best are probably the ceramic block types as they are large and dissapate the heat easily, they're also very load tolerant. If you use smaller resistors then they can get quite hot.

[cairojay]

I've just fitted Oberon LED indicators to the front and rear of my bike and I bought the resistors to go with them which is just a simple link between the indicator and the power supply. In the end I didn't need them and I wired them in directly. I was told that the power supply for the indicators is regulated through the ecu on the S4RS and so it just gives the LEDs the power they need. Anyway, they work brilliantly without the resistors.

[jezzamondo]

Interesting Cairojay! I found some nice bright amber LEDs mounted on a board from Superbright LEDs in the states that fit neatly inside the aftermarket Ducati alloy housings. I've only fitted the rears so far. They certainly flash faster, but I think maybe not too fast. So you are saying maybe with all LEDs in place they might regulate themselves OK? Do you know how fast yours are flashing?

[cairojay]

I fitted the fronts after the rear ones as I had to drill new holes in the front bracket. The rear ones worked normally independently of each other so maybe it's something to do with the Oberons. the flash rate is exactly the same as the regular ones but I get the impression that its a bit hit and miss. you could try wiring them all up but I've no idea if this would work.

Sorry to be so vague!

[jezzamondo]

Thanks again - I've ordered the fronts now anyway, so will make it all work somehow! I've now got bigger fish to fry with my intermittent cut out (in another lonely post) which is probably down to upsetting those sensitive electrics... If I do get it all working, the inserts look really bright in the DP mounts, so I'll post a photy

[jezzamondo]

Update on this - with front & rear LED indicators mounted & no load resistors, I can safely say the S4RS flashes them at about 150 per minute which I think is not going to make it thru MOT. They look well sharp tho. Also fitted a superbright.com (BA15 18 High Power LED Tower bulb, Red 1157-R18-T $17.95) WOW! Really bright great light, easy swap, expensive but very pleased- recommended.
I'm not confident that just 2 load resistors will work on the S4RS, looking at the wiring diag it seems like the indicators are all independent & I was running 21W bulbs up front (double normal) with LEDs on rear & still flashing fast. So I'm tempted to try a 15R 10W resistor for each indicator - anyone with thoughts on this?

[vtaggart]

Photos please:mand:

[Capo]

Resistors should be wired in parallel to the load. I did them front and back but am gonna try removing the back set to see what happens.

[jezzamondo]

Photos imminent!

What resistors are you using Capo?

[uksurfer]

if it helps, i got Arcol HS25 10RJ on an S4, just wired parallel on each of the rear indies
fleabay purchase i think!

[Capo]

The same as UK Surfer.

[jezzamondo]

OK thanks for update, I'll get some ordered - any neat solutions for mounting?

[uksurfer]

i mounted mine on a little plate cus of the heat, under the seat, HTH

[Capo]

I made up mounting plates and had them anodised, fixed the resistors using aluminium allen bolts, I had to enlarge the mounting holes in the resistors I also used thermal conductive paste between the resistors and the plate, tho I don't think is necessary, some report that they get hot but my observations contradict that, dont forget the current also flows through the semiconductor device mounted on the instrument PCB, its about the size of your thumbnail.

The resistors have eyes on the connections, hook the wires to them then solder, heat shrink over the joint. I soldered both wires (for the parallel conection) brought out as fly leads, you could do it with a single lead and effect the parallel conection elsewhere by the use of a jumpered connector.

For the front I mounted the resistor onto the airbox using two redundant (designed for the seperate imobiliser on the S4) threaded bosses, had to pack the plate out with a washer (glued in place) for the nuts on the resistor securing bolts to clear.

I'm not sure if the S4Rs has this type of air box, here is a picture

http://i295.photobucket.com/albums/mm143/Tarugo996/P1010169.jpg

For the rear, I mounted the plate on the rear fender, as this is curved, 10mm spacers were required, I used dome headed screws with rubber washers inserted from below to keep out any water that may get thrown up by the rear wheel.

http://i295.photobucket.com/albums/mm143/Tarugo996/P1010170.jpg

[jezzamondo]

That is comprehensive! Beautiful work Capo & thanks for the detailed posting! To date, I've just tried 15R in parallel with each indicator which gives the correct flash rate, about 12W an indicator. Then I put the same loads just on the rear in parallel (2x15R=7.5R, 25W right?) & I was back to rapid flash mode! It would seem the S4RS ('06) needs a load on each indicator...

[jezzamondo]

Thanks Capo, awesome post! You deserve multiple virtual beers for that, even real ones if I get the chance! I got the right flash rate in the end with 15R 7W on each indicator, then tried stacking them just on the rear (in parallel, 2 x 15R= 7.5R, right?)- no joy, my bike wants a load on each & every indicator. Just starting to wonder if cairojay hit on something & maybe the S4RS can be "convinced" LEDs are OK. Hope someone out there knows because I really don't think i can match Capo's attention to detail for mounting load resistors...

[Capo]

Thanks,

BTW I got the front mounting arrangement idea from Stafford credit where it is due.

With regard to resistors in parallel, The total resistance is calculated by adding the reciprocal ( 1/Rn ) value of the individual resistances instead of the resistances themselves (as is the case with resistors connected in series). The formular looks like this (1/R1 + 1/R2 + 1.Rn = G) the resultant is a value known as Conductance, symbol G with the units of conductance being the Siemens, symbol S. Conductance is therefore the reciprocal or the inverse of resistance, ( G = 1/R ). To convert this conductance sum back into a resistance value we need to take the reciprocal of the conductance giving us then the total resistance, RT of the resistors in parallel.
One important point to remember about resistors in parallel, is that the total circuit resistance (RT) of any two resistors connected together in parallel will always be LESS than the value of the smallest resistor

The circuitry on the Instrument PCB incorporates a comparator circuit that looks at the load on the indicator, if the load is lower as would be the case with LEDS, then it thinks a bulb has blown and increases the flash rate. This is a design factor and I believe is a requirement by law.

Now interestingly, later models have the ability via 'programming' to select either incandescent or LED loads, it probably does this by switching to a second comparator circuit.

If I could get my hands on a spare board, I want to investigate this further so I can get rid of the resistors.

Here is a picture of the PCB with the indicator 'relay' identified under the shaded circle.

http://i295.photobucket.com/albums/mm143/Tarugo996/P1000871copy.jpg

[jezzamondo]

Excuse the double posting - thought first hadn't gone up, I'm not quite as excitable as all that... Thanks for the image - is that your S4R? So the load I put on the rear still should have been enough to convince the board all bulbs were present but didn't & Cairojay is reporting his indies are flashing at the right rate (although it might be interesting to know what that rate is if you are still following this cairojay) so I have a cleverer system - maybe a dip switch on the board? Perhaps there's a link that can be removed/put in? Can't see anything in the manual or online about it. Anyone?

[Capo]

Therein lies the rub, there is no technical information available on this PCB, a sample that could be examined in detail would provide the information to alter the comparator circuit.

[jezzamondo]

Some pics of the LEDs in action. I've not got the skill with a camera to capture the colour which is really iridescent, particularly the red globe through the red housing. The "white' of the number plate bulb replacement is that sharp icy white which looks cool too. All lights are unmissable now, result:eyepopping:!

links for components if anyone is interested:

high intensity bulb (http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fspecs%2F1156-x18-T.htm)

Thing I used for indicator (http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fspecs%2FuniversalPCB.htm)

Have written to Ducati Capo to see if they can enlighten us on the dash circuitry, I can't see myself stumbling on another dash anytime soon & I've got an MOT to get thru!