Brake Lights

When my brake lights went out, it turned out it was because the relay under the hood was in bad condition. The relay eventually failed outright but before that was a few weeks of intermittent craziness. Rust, corrosion, even a wire hanging by a thread seemed to have caused it. Once it was replaced and the corroded terminals replace with new, all returned to normal. It was giving odd symptoms that would change over time because of it's poor condition.

Also have an auxiliary pump under the hood that creates a vacuum that operates the doors for the dash comfort vents. Heat, straight vent, AC...that sort of thing. Turns on and off at seemingly random times when there's a leak in one of the hoses.