RUMBA FAN1 control

 /****************************************************************************************
* RUMBA pin assignment
*
****************************************************************************************/
#if MOTHERBOARD == 80
#define KNOWN_BOARD 1

#ifndef __AVR_ATmega2560__
 #error Oops!  Make sure you have 'Arduino Mega' selected from the 'Tools -> Boards' menu.
#endif

#define X_STEP_PIN         17
#define X_DIR_PIN          16
#define X_ENABLE_PIN       48
#define X_MIN_PIN          37
#define X_MAX_PIN          36

#define Y_STEP_PIN         54
#define Y_DIR_PIN          47
#define Y_ENABLE_PIN       55
#define Y_MIN_PIN          35
#define Y_MAX_PIN          34

#define Z_STEP_PIN         57
#define Z_DIR_PIN          56
#define Z_ENABLE_PIN       62
#define Z_MIN_PIN          33
#define Z_MAX_PIN          32

//to use Z_DUAL_STEPPER_DRIVER in Marlin
#define Z2_STEP_PIN        26
#define Z2_DIR_PIN         25
#define Z2_ENABLE_PIN      27
#define E0_STEP_PIN        23
#define E0_DIR_PIN         22
#define E0_ENABLE_PIN      24

//#define E1_STEP_PIN        26
//#define E1_DIR_PIN         25
//#define E1_ENABLE_PIN      27

#define E2_STEP_PIN        29
#define E2_DIR_PIN         28
#define E2_ENABLE_PIN      39

#define LED_PIN            13

#define FAN_PIN            7
//additional FAN1 PIN (e.g. useful for electronics fan or light on/off) on PIN 8
#define FAN1_PIN           8
#define PS_ON_PIN          45
#define KILL_PIN           46

Quote
Dust
Just use m42

eg "m42 p8 s255" should turn your fan1 full on. ...