my 1987 325 wont start and wont crank.new battery.

Could you give a more detailed description of what the car does? Like does the starter turn at all? Do any lights come on?

Could be one of the main relays failing (three, I think, in the engine compartment). When relays are very old they react differently to different temperatures. Could also be a poor ground or hot lead going to your battery or starter. Also your starter solenoid may be failing. Though more details should be furnished.

Disconnect the negative cable at battery check current draw .No more than 25 milliamps draw ok .The other way less complicated is to see if test light lights,start pulling fuses till light goes out.That is were your draw is.