A freind has brake lights in park but when in gear nothing. She has taken it to a “mechanic” & has gotten the line that the brake lights are purportedly on a curcuit to a brain. I have never heard of sucha thing. I’m thinking a bad neutral safety switch. The other lights work ok, turn,bk up, tail lights.
Just so that we all know the type of vehicle that you are referring to, are you located in North America, or in Europe?
I ask because there has never been a Ford Fusion wagon sold in the US.
By contrast, Europeans can buy a small 5-door hatchback called the Fusion, even though it is a totally different car from the US Fusion. The Ford Fusion sold in Europe (and possibly in South America) is a stretched version of the Ford Fiesta.
The brake lights are activated by a switch on the brake pedal linkage, not a “brain”. When you step on the brake, a circuit is closed and your brake lights go on!!!Works the same way as the door switch turning on the interior light.
You are right that there is a connection to the gear shift as well. The mechanism is problably no more elaborate than the “mechanic’s” brain.
A good mechanic can find the real fault in very little time.
If it was the brake liht switch, would it not have brake lights while in park with the engine running. As far as the make, she calls it a “wagon”, to me it"s a 4 door hatchback.