2nd extruder ambient temp 500/0

Hi, I can't get my board to change to 2 extruders. It gives an ambient temp of 500deg and no option to heat the 2nd extruder. It has worked before and i'm using same changes as before. Any help will be appreciated.

I'm guessing you have changed the firmware? Could you upload your configuration file? The standard firmware is not configured to run two extruders/hotends.

ps. I'm curious how you managed to add a second hot-end to the materia. Please post some pictures.

Hello, I have the same problem. Did you solve it?. I used the marlin downloaded from Prusa i3 Rework Firmware - RepRap. It looks like the thermistor scale is inverted. I switched the thermistors and the new one have the same indication, 474/0. When I desconect the thermistor says 500/0 (the diference is ambient temp 26ÂșC).
Changed:
#define MOTHERBOARD 34

#define EXTRUDERS 2

#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_1 0
//#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_BED 1

#define HEATER_0_MINTEMP 5
#define HEATER_1_MINTEMP 5
//#define HEATER_2_MINTEMP 5
#define BED_MINTEMP 5

#define HEATER_0_MAXTEMP 300
#define HEATER_1_MAXTEMP 300
//#define HEATER_2_MAXTEMP 300
#define BED_MAXTEMP 150

Best regards.
(Sorry bad and rusty english)

Solved!
Use #define TEMP_SENSOR_1 1 instead of #define TEMP_SENSOR_1 0