had this exact same problem yesterday when I was sticking my girl back together. I was in the middle of fitting the gipro gear indicator I bought and thought I had done something wrong.
symptoms.
turn key to first stage and ignition is OK , then if I touched a connector it started to do the self check over and over again and was cutting in and out.
turns out it was the loom connector for the dash as I had removed it all for deep cleaning.
I found it to be the larger more squarer looking block inside the left front fairing. luckily I had this all off as she was being built back up.
I cleaned the connectors and put some grease on the contacts, had to slightly ( and I mean slightly) twist the prongs inside the connector housing so that they fit snug again.
ensure I got a good fit when going back together and did several ( maybe 30 times) checks and wiggles of the connector to see if the problem was gone and hay presto, done.
could probably do with a new connector on mine as I man handled it a bit and its a little scrappy but as I work in the electronics industry I could probably get something to work better.
so, all you need to do is make sure connections are clean and a good fit, plus don't mess with connections while the ignition is on, not until you really think you have sorted the problem out, just in case.
hope this helps.