E30 Zone

Are haynes manuals the best for wiring diagrams or is there a website or a pdf link etc?

Car is a 1989 318i m40

Thanks

haynes is not always right it is best to cross check it with other books sites etc i put a alarm once in a 316 and the central locking wiring was different to the one in the haynes book
i have about 3 or so books just on the e30 you can never be 100% plus some one may have been doing there own wiring, car wiring is a real pain but simple jobs should not cause too much hassle and haynes should be ok