1991 BMW 525 electrical

My 1991 525i is having electrical problems I think, when I start the car theres a small pop in the engine and it wont turn over the first time
the second time it turns over and idles at about 3000 rpm's then after about 3 minuets it idles rough and low also the tach and speedometer dont work as well as the windows and sunroof also the car will not shut off by key I have to dump the clutch to stall it out to get it to shut off