KTM accessory sites .....
- Thread starter Giles
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I didn't say you were using canbus to power the horn but the 'existing positive wire' which you're going to trigger the relay with is on the canbus network and hence is subject to canbus sensing / trip. This may be absolutely fine if it's only setup to trip on high current.
You may have highlighted a potential problem. I have a Stebel Nautilus mounted in my 1190 via a relay and all seemed to work well. However, the other day, I had occasion to give a prolonged blast to an idiot in a car who was heading towards me on the wrong side of the road.
The Stebel certainly woke him up (which the OE horn would not have), but was immediately followed by a "general failure" warning on the dashboard. The bike seemed to be perfectly ok and I was close to home, so not a problem, and when I re-started the bike 30 mins later the warning had disappeared. I had this happen once before when the bike got hot in heavy traffic, and the warning disappeared after a stop for fuel.
It may have nothing to do with the horn, but seems too much of a coincidence. When I get the chance, I will give the horn another long blast to see if it happens again.
Matt it should have read; Your not using the canbus to power the Relay, however you no what i mean fella, the canbus will not power any aftermarket accessory on its own and such is why you need to fit a switched relay and use the existing wires only to trigger the relay and it should not need high current to trip the relay .
I'd start by replacing the relay it could be breaking down, because the switch does not need high current, did you take the live in from the battery !
I think we're at cross purposes here (possibly?).
CANBUS on its own doesn't power anything it's just the 'controller area network' which is used to sense the load on various parts of the loom and send and receive control signals to 'intelligent' components on the network, simplifying the loom, reducing the number of cables required to be used and eliminating many fuses.
In the case in point, CANBUS is sensing the load on the section of loom powering the OEM horn. Now it might just be looking for a 'high current' condition (essentially modelling the behaviour of a fuse) in which case any component which draws less current than the OEM horn (including the coil of a relay) would work fine but it might be looking for the load to fall within a certain range in which case the relay might be a potential problem due to a 'low current' condition...
I've no idea if this is the case and short of getting the information from KTM (unlikely, I'd have thought), it's probably just a case of suck it and see...
CANBUS on its own doesn't power anything it's just the 'controller area network' which is used to sense the load on various parts of the loom and send and receive control signals to 'intelligent' components on the network, simplifying the loom, reducing the number of cables required to be used and eliminating many fuses.
In the case in point, CANBUS is sensing the load on the section of loom powering the OEM horn. Now it might just be looking for a 'high current' condition (essentially modelling the behaviour of a fuse) in which case any component which draws less current than the OEM horn (including the coil of a relay) would work fine but it might be looking for the load to fall within a certain range in which case the relay might be a potential problem due to a 'low current' condition...
I've no idea if this is the case and short of getting the information from KTM (unlikely, I'd have thought), it's probably just a case of suck it and see...
Yes agree matt the canbus is only a network cable, its supposedly 4v however if you attach a low impedance current sink to the CAN bus (less than ~60ohms) the canbus will fail.
So if we assume a 50:50 mark space ratio, with the nominal +-2.5v voltage the most power you could ever pull from a canbus is theoretically just 0.104 Watts i think !
So if we assume a 50:50 mark space ratio, with the nominal +-2.5v voltage the most power you could ever pull from a canbus is theoretically just 0.104 Watts i think !
So, I think we're saying the same thing here?...
As the network and the 12v loom are isolated (apart from at the nodes and controllers), the canbus will not in itself be affected by what you connect to the horn terminals (otherwise a trivial component failure like the horn could bring down the network and shut down the bike, or at least portions of it).
So, (if my assumptions above are correct) it's just a case of what parameters the canbus load sensing is looking for on the 12v section that feeds the horn. If it's just high current then a relay coil will be fine, if it's more complex, then the low current drawn by the relay coil might be an issue.
I'll admit that my experience of this type of controller network comes from writing code for industrial SCADA systems but from what I've read up on vehicle canbus systems they work along broadly similar lines in terms of protocols, isolation and fault tolerance etc.
Anyway, I'll dip out of this discussion now. If it were my bike, I'd try a basic relay setup first and if it proved unreliable, I'd get a meter out and determine the load drawn by the OEM horn. Then you could broadly replicate this load by adding a resistor to the relay coil feed. I can't imagine that the controller is looking for anything more complex than a load range for a horn...
Yes, I took the live straight from the battery via inline fuse.
I will test it again and see what happens.
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