What is causing the battery to drain on saab when using brakelights

Are you seeing a gauge dip? The brake lights require a lot of power and your foot is off the gas so engine speed is low. That's going to draw power from the battery.

...well the Brakelights power is not free...got to be taxin' the 'lectrical system like 15 amps or so---that power is gotta come from somewhere, if you're at Idle, your poor alternator isn't turnin' fast enough to keep up with the drain of the Powerful set of brakelights and has to start getting power from your battery.....which probably isn't skippy and fresh. Hose it off and clean the terminals to make a GREAT connection. Your brakelights won't get all fadey then....unless your battery is kinda toasty...in which case get it load tested, where they'll tell you that you need a new battery.

great question maby i can help if you have a dead battery every time you have the brakes as normal and then disarm them from fuse and your good,then the brake switch is not releaseing and the lights sit on all day,as they work without key on ! the consumton as normal is minute