Green’s Dictionary of Slang

(drugs) a heavy user of amphetamines.

1979		J. Homer Jargon.
c.2003		Detective K. Reeves ‘Dangerous Drugs and Their Effects’ on the D.A.R.E. page of Harnett County Sheriff’s Office 🌐 ‘Methamphetamine: Crank’ [...] Crank makes the user feel that he or she is in total control, very alert and energetic. These effects last for several hours even days depending on the amount. The human body can live without food and water for long periods of time, but the human body must have rest. The human brain without rest begins to short circuit, usually the user ‘CRANKER’ begins to go into paranoid episodes.