Yeah, Rostras are really quirky about going into diagnostic mode. At a guess, I bet about 1 in 3 units simply will not enter diagnostic mode. It seems to be linked with which control pad is being used but at any rate, it is a common and frustrating problem.
That said, you absolutely do not need to use the diagnostic mode at all. The unit can be tested on the road or, with some risk IMO, on the centerstand. The unit will NOT work properly on the centerstand though and if you do try that method you have to disengage the unit immediately after it engages; the test is really only to see if the CC has sufficient and correct connections to work, not to see if it works correctly (it absolutely will not work correctly). This is another place the 'engaged' light is handy- as soon as that light illuminates, disengage the cruise control or kill the engine. If left on, the CC will surge badly and really rock the bike on the centerstand pretty violently and that has the obvious risk of knocking the bike off the centerstand with the rear wheel already turning at some stunning rate.
Finally, tinker around with different ways to enter diagnostic mode; different modes of button sequences work on different switch units. No hard in trying all the methods mentioned in the Rostra manual even with the 'wrong' switch- nothing can be damaged and the worst thing that can happen is that none of them will cause the unit to enter diagnostic mode.
Best of luck with it.
Brian
I have to begin with by saying that I dislike that my first post here is concerning this topic as I see that are plenty out there from doing a simple search. But I am unable to find my problem. This is likely because I just did not read enough
I purchased the Rostra from Murphs kits with the control pad PN 250-3592. Mounting and wiring went fine.
I was going into diagnostic mode when I realized I read the instructions that Brian was great enough to write out wrong, I had the NSS attached and the VSS not attached. So all the tests up until the VSS test ran successfully. At that point I went back to instructions (actually read them) and disconnected the NSS and connected the VSS. Now I am unable to get into diagnostic mode at all.
This is a very brief and most likely vague description of what is happening but I have to get to work.
Thanks for the help.