Rostra Cruise - Help Please

ccapse

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Hi, just wondering if you guys have ever encountered anything like this?
Ive installed a 250-1123 on a Hayabusa gen2 using a CCS100 keypad. It all works perfectly except for one strange trait.
If the unit is turned off, and I apply the rear brake, then when I release the rear brake, the unit turns on - intermittently. My install uses the relay-brake-light option as The gen2 has a LED brake light.
I dont have the issue when I apply the front brake.
The red wire and the activation for the brake light relay are connectd across the rear brake light switch, but front brake switch is in parallel to the rear so it seems odd I only have issue with rear brake.
I Originally had the issue constantly but I swapped to a different relay and now the problem is intermittent.
Both the grounds that go to the relay and the overall ground for the Cruise actuator go to the same bolt on the subframe.
Does anyone have any thoughts on what may be causing this annoying trait?
I know FALQN had a similar issue but he had a brake light modulator installed and my brake light is stock.
Any incites would be much appreciated.
Cheers Chris
 
My install is just setup to see the brake light actuated if I recall. It doesn't know whether the front or rear brake actuates the light. The relay to the cruise is attached to the brake light. The system will also cancel if there is a big, rapid rpm change, like when you pull the clutch for example. The install you are describing seems overly complicated, not sure if that is your problem. Not sure this is helpful but it's all I got! Good luck, the cruise is one of my favorite mods!
 
Chris did you get anything worked out on this? I've installed no less than 10 cruise systems vacuum and electric so more than happy to walk through this with ya.
Hi Captain, no luck yet. I will take you up on your kind offer of help. Im off on an endurance ride this weekend but will message you next week with more detail and perhaps this can be 'nutted out'. The most frustrating thing is that the issue only appears when using the rear brake, which just doesnt make sense. Cheers Chris
 
I am reading that this unit may have a diagnostic mode to indicate correct wiring?

I wonder if that relay ground is being energized, sending power to the actuator ground, and that happens to power the unit. Put a voltmeter on that ground point, with reference against the negative battery terminal. Does voltage build up at that connection?

When thinking what are the chances that one or both relays is bad, the change when swapping relays sounds like one of those circumstantial events. I cannot help but think that in both relay cases something is touching something, or there is a ground problem, resulting in the energizing of the negative side of the circuit.

Are there several power taps to accomplish this? I highly doubt this but heck have to check everything, so make sure none of those are shorting against anything.
 
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Let me go find some of the threads I have posted instructions in the past. There is a diag mode that allows you to to things and get responses back in light codes.. My first check through would be to ground to the battery and see what happens there.
 
To all you guys who have taken the time to respond to my query, thank you very much. I got back safely from my endurance ride and really enjoyed using the Rostra especially on the 'longest day' 1200km in 14hrs.
Throughout the ride I Tried to determine if there was any pattern to my rear brake issue but nothing seemed obvious. I could go for long periods where the issue didnt appear and other times when it was quite frequent. Ive decided to live with it for now. Frankly I cant work up the enthusiasm to pull all the plastics off again. I will have another look at the earths next oil-change when I have to remove the plastics anyway. For now Im concentrating on getting my R1150GS ready for some unsealed roads planned for Easter.

I do have one other question though. Ive bought a banjo bolt pressure switch that is sometimes used in front brake master cylinders to activate brake lights. I was thinking of replacing the banjo at my clutch slave cylinder with it and hooking it up to the Rostra clutch deactivation circuit so when I pull the clutch, hopefully the banjo switch will activate and be able to deactivate the Rostra if it is engaged. I am tapped into one of my ignition coils but the only time I tested that by pulling in the clutch, the Rostra didnt seem to disengage before I chickened out and released the clutch before the engine hit the redline so Im looking at this as an alternative safety. Any thoughts?
 
Just my thoughts, pull the plasitcs and recheck. It should disengage, if it doesnt you are facing a safety issue that I couldnt live with.
 
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