Originally Posted by loudnfast
Im having the same problem this morning on my 535i 1990 .batterys good , but its not starting ,lights are bright ,central locking good, but my windows wont work and i get nothing when i crank it...was fine at 2am lastnight .any one have any ideas?
Get a voltmeter and connect to your battery - if you have 11 volts or less your battery needs to be charged or replaced. Lights, central locks, etc take minimal amps to operate, whereas your starter draws almost 200 amps to crank motor. Another thing to check is cables on starter - they corode easily because they're exposed to moisture, grease, dirt etc... wire brush cable ends - ALL of them and at both ends
Re: "Snums" - it too could be a dead battery - try the above & charging battery - also you might have a flat spot in starter - I'm betting it's a combination of dirty/coroded cable ends & a weak battery