Hello all,

I am working on replacing the head gaskets on my old 1980 Buick. While on this adventure, I stumbled upon a curious little black button. This button is attached to a bracket, which is mounted on top of the intake manifold. I've attached a picture of this button. Anybody know what this button does (and don't tell me to "push it and find out", smart-asses). It is a 1980 Buick Lesabre, with the Pontiac-built 4.9L 301 cubic inch engine. Any help would be greatly appreciated. Thanks!

 

I ended up getting help from people on a different forum. This is a throttle actuated A/C compressor cutout switch. It basically turns the A/C off when the throttle is wide open. The throttle arm itself actually pushes the button when the throttle is wide open. Temporarily turning off the A/C gives more power to the engine when you step on the pedal.

 

That's really interesting! I can't say I have ever seen something like that before. Thanks for reporting back with your findings!