G5. I'm just pre-empting an on-the-road problem, hope it never happens...
I've read somewhere that if the malfunction indicator starts flashing, you lift the seat orf , find a loose wire, put that to earth, count the flashes to find out what's wrong. (My service manual is on order from Gordon May). Taking the seat off, I've found a loose greeny/blue female bullet connector and a loose 6 terminal white connector. If the item in question is the female bullet connector, I'd have to make up a wire with a free end and a male bullet plug.
Only done 100 kms on the G5 so far, checked the brake light - not working. Bulb ok, The brake switch plunger wasn't being pulled enough. (Is there an adjustment?) Otherwise the spring must have stretched. Temporarily fixed problem by backing off rear brake adjust, now means quite a long movement of brake pedal.
cheers Larry