| I've seen a couple of 1098/1198 of late with similar problems and they've been caused by corroded ignition relays. Not enough to fail, but enoughh for them to get a bit hot and throw a wobbly.
They are tucked away to the RHS of the battery tray, just behind the water pipes. You can get access by taking off the battery cover and pulling the upper pipe forward a little.
Just as an aside, the alarm activation should be disabled with ignition on. |