How to move stepper driver to another slot of RAMPS?

Hi,
I am using Arduino Mega / RAMPS. The extruder's motor has all 3 jumpers under the Pololu shield, but it runs FAST, as if no jumpers (and does not run at all with no jumpers).
I have another reprap, and when connected to its shield (same firmware), the motor works fine.
So I conclude that something is wrong with a) driver, b) RAMPS and c) Arduino.
But using another driver does not solve a problem.
So I want to move driver to a free (5th) slot of RAMPS, the one where a second extruder would be, if any.
I use Sprinter.

Question: how to tell the firmware to work with slot of second extruder and to ignote the first?

Thank you.

P.S. Maybe I am wrong, so any suggestions are welcome. Once again, the motor spins FAST, many (dozens) of times faster than normal 50 mm / min. All 3 jumpers in place. Motor is fine (tested with another Reprap). Shield is probably fine, at least, replacng it does not change a thing. No extra heat or sounds.

P.P.S. Tried another Arduino. Same thing. So it is RAMPS. Still switching to another slot (2nd extruders') seems like a good idea.

Edited 1 time(s). Last edit at 11/01/2016 05:28PM by Fizpok.

Sounds like there is no voltage going to the pins but that would not explain why it does not work with no pins.
The easy fix is to use second extruder (E1) pins.
You don't say which version of marlin you are using but this may help.

In pins.h change
#define E1_STEP_PIN 36
#define E1_DIR_PIN 34
#define E1_ENABLE_PIN 30

to
#define E1_STEP_PIN -1
#define E1_DIR_PIN -1
#define E1_ENABLE_PIN -1
This will disable second extruder

Change axis (??) one not working
Your numbers may vary use E1 pin numbers
#define Y_STEP_PIN 36
#define Y_DIR_PIN 34
#define Y_ENABLE_PIN 30

You will then have to build and load to Arduino Mega

A little correction: I don't need to disable second extruder - I need to ENABLE second extruder, to disable the first one, and to connect extruder to a second slot instead of first.
So I will ser E_... to -1, instead of E1

Edited 1 time(s). Last edit at 11/02/2016 01:36AM by Fizpok.

Question: ok, I have disabled the first slot for extruder and installed driver in the secons slot (E1), and connected extruder to it.
Should I somehow tell the software to send extruder commands to the second slot instead of first?

I am going to use:
#define E_STEP_PIN 36//26
#define E_DIR_PIN 34//28
#define E_ENABLE_PIN 30//24

#define E_1_STEP_PIN -1//36
#define E_1_DIR_PIN -1//34
#define E_1_ENABLE_PIN -1//30

correct?

Edited 1 time(s). Last edit at 11/02/2016 01:49AM by Fizpok.

Ok, in the E1 slot, same picture. Extruder spins fast. Very.
Any suggestions?

After playing with pot, I managed to make extruder spin with no pins. As expected, it is even faster.
So, the question is: pins do work, but speed is too fast.
Where in soft should I ook for problems?

Micro stepping is a hardware function, easy to check, the pololu pins ms1,ms2 and ms3 should all be near 5v

I suspect you just have a eeprom issue... so the steps/mm are not what you set in firmware but what is in eeprom.

reset your eeprom to your firmware settings

Thanks. It worked!