rev's dropping when braking, only when the motor is cold and lights are on Options

[xkillerx]

this has been happening for quite some time now. during night (aka lights on) when i brake, the rev's drop down to 200-400 rpm's. once it even stalled. during the day (lights off) this never happens. when the motor warms up it doesnt happen either. it's really weird. it doesnt matter if i'm in neutral or in gear or clutch pedal depressed. the car is a 97 euro st stock, has a b'f' aftermarket audio system (thanks k-esd for the wiring instructions) and the only thing wrong with it is a slippy clutch (which hopefully i'll replace soon). other than that it's perfect. any ideas?

[bindertch]

Depending on how many amps or watts you system is it could be using more power than the alternator can supply. Is your stereo on during the same times that it wants to die? Also like quicknstyle said it could be your charging system. I would try to get it to repeat it with different things or take it to a shop that can test you alternator and charging system.