Alternator warning light actually functions as a brake pedal application reminder Options

[Tdskip]

Good morning gentlemen, hope it’s been a good week so far.

My alternator warning light goes crazy anytime I step on the brakes or use a turn signal. I confirmed that I’ve got 13.6 V at the battery with the car running, so it appears that I have a wiring issue somewhere, most likely behind the dash I assume.

I was hoping to see if anyone’s had a similar issue and what they did to resolve it to help narrow my focus before I start digging in.

Thanks!

[Spoke]

Here's the simplified circuit for the alternator, battery, and GEN light. When you turn the key to ON before cranking the engine, the GEN light sees 12V from fuse 9 and 0V from the VR as the alternator isn't turning.

Once the engine is cranked and started the GEN light current bootstraps the VR and alternator into operation.

If when you press on the brake the GEN light comes on, then either the voltage at the fuse drops or the voltage at the VR drops. One of them has to drop for there to be a difference in voltage and the GEN light comes on.

One way to check this is to hook your voltmeter up to either side of the GEN light and drive the car. Obviously the wires would have to be securely fastened so they don't come loose or you holding the voltmeter.