They work when I have the headlights on and If I gently squeeze the front lever but they go if I push it any further. They won't work at all with the back lever.This has also stopped my electric start working except if I use it when I gently squeeze the front lever. I have a 2007 Kymco miler 125 if it helps.
The electricity flows from a switch. For the brakes, front and rear, you should be able to activate the switches independent of the levers. Test and see what you can learn. The brake switches should be completely independent of the starter switch, but since the front brake switch and starter switch are on the same harness, check the connection. It may simple come slightly unplugged. My guess is that you have a short in a wire somewhere, or simply a bad ground. Tracking electrical gremlins is the worst pain there is on a bike.
For the rear brake it sounds like all you have to do is adjust the switch on the backside of the footrest.It should have a long spring attached to the brake lever and the switch.Adjust the switch by turning the nut on top of the bracket-all you want is the spring to be straight,not tight-it will then activate the brake light when you step on it..The front sounds like a faulty switch.