Help with LED indicators/turn signals

[Harald Kapp]

this is confusing the dash micro?

Rather possibly.
Could you run teh front lights through the same auxiliary relay as the rear lights? This would reduce the load on the flash controller considerably.

 

[stuart cox]

Would adding another 10w resistor in series with the existing 10w resistor reduce the load also? I have been told to try that by a electrician friend. The 10w resistors are 10.4 ohms each.....

 

[Harald Kapp]

when you add two resistors of the same type in series the power dissipation is reduced to 1/2 of the dissipation of a single resistor.

However I think you're barking up the wrong tree: the controller is obviously happy with the LEDs when powered by the battery alone. Therefore it is most likely that the issue arises from disturbances (noise) on the powre supply lines when th eengine is running. There are a few possible sources, mainly:
- noise from the alternator
- noise from the ignition
Both noise sources may be reduced by a filter in line between battery and flash controller.
On the other hand an automotive (or motorbike) controller should have been constructed to withstand these common sources of noise.
What about the battery? Is it in good shape? What is the battery voltage with the engine off and waht with the engine on? A worn out battery may have a high internal resistance which in turn may lead to increased noise with the engine running compared to a good battery.

 

[Bluejets]

The dash micro, if it is this particular model, is load dependant. I imagine Ducati were able to forsee the possibility of LEDs replacing the standard bulb and allowed for it in the programming. Have no idea what this actually involves but wondering if you have taken a peek on their forums?

Cheers Jorgo

 

[stuart cox]

The dash micro, if it is this particular model, is load dependant. I imagine Ducati were able to forsee the possibility of LEDs replacing the standard bulb and allowed for it in the programming. Have no idea what this actually involves but wondering if you have taken a peek on their forums?

Cheers Jorgo

Thanks Jorgo

I have looked in to reprogramming the signals to LED but although it is available on some models it is not on mine!

 

[stuart cox]

when you add two resistors of the same type in series the power dissipation is reduced to 1/2 of the dissipation of a single resistor.

However I think you're barking up the wrong tree: the controller is obviously happy with the LEDs when powered by the battery alone. Therefore it is most likely that the issue arises from disturbances (noise) on the powre supply lines when th eengine is running. There are a few possible sources, mainly:
- noise from the alternator
- noise from the ignition
Both noise sources may be reduced by a filter in line between battery and flash controller.
On the other hand an automotive (or motorbike) controller should have been constructed to withstand these common sources of noise.
What about the battery? Is it in good shape? What is the battery voltage with the engine off and waht with the engine on? A worn out battery may have a high internal resistance which in turn may lead to increased noise with the engine running compared to a good battery.

Thanks Harald. What I don't understand is that without the front signals connected, the rear signals flash correctly with the engine running, leading me to believe that there is an issue with the added load from the new front signals. Also with the original front signals connected they all flash correctly with the engine running. Surely if there was interference issue from somewhere it would have an effect regardless of the set up?

I have a couple more resistors arriving today, I will try the wired in series idea anyway, nothing to lose! I'm hoping it will reduce the overall load to close to the original setup!

Thanks Stu

 

[Bluejets]

Thanks Jorgo

I have looked in to reprogramming the signals to LED but although it is available on some models it is not on mine!

So are you saying it is not micro controlled but rather mechanical/electrical controller?

 

[stuart cox]

'So are you saying it is not micro controlled but rather mechanical/electrical controller?'

I'm not totally sure to be honest, I know there is no external mechanical relay and have read that the flasher is built in to the dash!

Sorry about calling you Jorgo by the way, I actually put Bluejets but my computer decided that it knew better!

Thanks Stu

 

[Bluejets]

Sorry about calling you Jorgo by the way, I actually put Bluejets but my computer decided that it knew better!

No problem....either is just fine.

Do you have a model number /year of your machine?
I'll try to chase up a wiring diagram.

 

[stuart cox]

Thanks, it is a Ducati Hypermotard 796 year 2010

 

[stuart cox]

Ok, so with the help of a friend who is a bit of an electronics whiz, we have finally discovered the problem. As I had thought the circuit in the dash that produces the flash is very sensitive to the amount of power loaded on the circuit. We have determined that it needs a 35 ohm resistor to bring the circuit back inline with the original. We connected a 6w bulb across the signal wires which measured 35 ohms and it sorted the 'pulsing when engine running' issue out. I have ordered a couple of 35 ohm resistors to replace the 10w resistors I had in place and fingers crossed everything should work as intended!

 

[Harald Kapp]

Glad you worked this out. Sorry for my insisting on the noise issue. It just happens to be so incredible that the controller is so sensitive.

One minor issue or question: How did you determine the 35 Ω? From basic rules it follows that R = V²/P = (12 V)²/6 W = 24 Ω not 35 Ω
I hope you matched the power rating of the resistors. At 35 Ω you need a power rating of P = V²/R = (12 V)²/35 Ω = 4.12 W per resistor. A 4 W resistor may suffice as the turn lights are operated only intermittedly.

 

[stuart cox]

Thanks for your help Harald.

To be honest I left the calculating to my friend, I have no idea how to work it out!!

But he came up with 35 ohms and told me to use a 6w bulb to test the theory as it measured 35 ohms and it worked!

Thanks again
Stu