Character controller not running or slowing while crouching.

Unity Engine
1

Dear community, I am fairly new for to coding in c# and I tried to get my character controller to be able to run and crouch.
I got him to crouch but not slow down, could anyone take a look at my code and help me solve this?

using UnityEngine;
using System.Collections;

[RequireComponent (typeof(CharacterController))]
public class FirstPersonController : MonoBehaviour {

	public float runSpeed = 20.0f;
	public float crchSpeed = 3.0f;
	public float movementSpeed = 5.0f;
	public float mouseSensivity = 5.0f;
	public float jumpSpeed = 7.0f;

	private Transform tr;
	private float dist; // distance to ground

	float verticalRotation = 0;
	public float upDownRange = 60.0f;

	float verticalVelocity = 0;

	CharacterController characterController;

	// Use this for initialization
	void Start () {
		Screen.lockCursor = true;
		characterController = GetComponent<CharacterController>();
		tr = transform;
		CharacterController ch = GetComponent<CharacterController>();
		dist = ch.height/2; // calculate distance to ground
	}


	void FixedUpdate (){
		float vScale = 1.0f;
		float speed = movementSpeed;
		
		if ((Input.GetKey("left shift") || Input.GetKey("right shift"))  ch.isGrounded)

		{
			speed = runSpeed;
		}
		
		if (Input.GetKey("c"))
		{ // press C to crouch
			vScale = 0.5f;
			movementSpeed = crchSpeed; // slow down when crouching
		}
		
		//characterController.movementSpeed.maxForwardSpeed = speed; // set max speed
		float ultScale = tr.localScale.y; // crouch/stand up smoothly
		
		Vector3 tmpScale = tr.localScale;
		Vector3 tmpPosition = tr.position;
		
		tmpScale.y = Mathf.Lerp(tr.localScale.y, vScale, 5 * Time.deltaTime);
		tr.localScale = tmpScale;
		
		tmpPosition.y += dist * (tr.localScale.y - ultScale); // fix vertical position
		tr.position = tmpPosition;
	}
	// Update is called once per frame
	void Update () {
		//Rotation

		float rotLeftRight = Input.GetAxis("Mouse X")* mouseSensivity;
		transform.Rotate(0, rotLeftRight, 0);

		verticalRotation -= Input.GetAxis ("Mouse Y") * mouseSensivity;
		verticalRotation = Mathf.Clamp (verticalRotation, -upDownRange, upDownRange);
		Camera.main.transform.localRotation = Quaternion.Euler (verticalRotation, 0, 0);

		//movement

		float forwardSpeed = Input.GetAxis("Vertical") * movementSpeed;
		float sideSpeed = Input.GetAxis ("Horizontal") * movementSpeed;

		verticalVelocity += Physics.gravity.y * Time.deltaTime;

		if(characterController.isGrounded  Input.GetButton ("Jump")) { 
			verticalVelocity = jumpSpeed;
		}

		Vector3 speed = new Vector3( sideSpeed, verticalVelocity, forwardSpeed );

		speed = transform.rotation * speed;


		characterController.Move ( speed * Time.deltaTime ); 
	}
}
2

You could try using a boolean :

public bool isCrouching;

//In your update function

if (Input.GetKeyDown(KeyCode.C)) { 
isCrouching = true;
}

if(isCrouching){
vScale = 0.5f;
movementSpeed = crchSpeed; // slow down when crouching
}