The alternator wiring does not specifically go to the ECU, but rather to your fuse box where by it powers every little thing else in the vehicle including the ECU. I am not Great at explaining this such as this Plainly, but I hope it helps make more than enough https://4age-20v-turbo-engine-for36925.blogoscience.com/38728235/how-much-you-need-to-expect-you-ll-pay-for-a-good-blacktop-4age