You don't say whether this is just the rear blinkers, or all four.
But there has to be an incorrect wiring issue, or a short-circuit.
It sounds like the brake light may be earthing through the blinkers, so there is either a wrong connection (probably under the rear number plate mount) or a break in the earth connection for the tail-light/brake light.
We will actually need more information to pin this down - like is the tail light affected? Or the front blinkers?
In the meantime I would have a close look at the connections in that little triangular cover beneath the mufflers. May be something pinched, separated, or wrongly connected under there.
But there has to be an incorrect wiring issue, or a short-circuit.
It sounds like the brake light may be earthing through the blinkers, so there is either a wrong connection (probably under the rear number plate mount) or a break in the earth connection for the tail-light/brake light.
We will actually need more information to pin this down - like is the tail light affected? Or the front blinkers?
In the meantime I would have a close look at the connections in that little triangular cover beneath the mufflers. May be something pinched, separated, or wrongly connected under there.