1980 Other Audi Models Engine refuses to roll

whenever i turn my key to start position, the ignition comes on but the engine refuses to roll, i normally hear a sound from the fuse/relay area as if there is partial contact, if i keep turning the key off and on it will surely crank the engine but before it does, it takes time if only i can see the the fuse box diagram translated in english.
i will be grateful if my request could be granted