My test method won't pass for some reason

I have here a test method for a cypher machine, but I'm not sure I've passed in the culture and type correctly. Below is my test class and further down you will find a copy of my original code.

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using WpfApplication3;
using System.Globalization;
using WpfApplication3;


namespace UnitTestProject1
{
    [TestClass]
    public class UnitTest1
    {
        CultureInfo current = CultureInfo.CurrentCulture;
        EncryptConverter logic = new EncryptConverter(); 
        public Type T(string type)
        {
            CultureInfo english = CultureInfo.CreateSpecificCulture("English");
            Type classtype = Type.GetType("English");
            return classtype;
        }

        public object value()
        {
            string plainText = "abc";
            char[] chars = new char[plainText.Length];
            string key = "=2/3E*45-`~6<>!,.7+8[]9|:0";

            for (int i = 0; i < plainText.Length; i++)
            {
                if (plainText[i] == ' ')
                {
                    chars[i] = ' ';
                }
                else
                {
                    int j = plainText[i] - 97;
                    chars[i] = key[j];
                    string val = chars.ToString();

                }
            }
            return new string(chars);
            //string val =  chars.ToString();
        }
        public static object parameter()
        {
            string plainText = "abc";
            char[] chars = new char[plainText.Length];
            string key = "=2/3E*45-`~6<>!,.7+8[]9|:0";

            for (int i = 0; i < plainText.Length; i++)
            {
                if (plainText[i] == ' ')
                {
                    chars[i] = ' ';
                }
                else
                {
                    int j = plainText[i] - 97;
                    chars[i] = key[j];
                }
            }
            return new string(chars);
        }



        [TestMethod]
        public void TestMethod1()
        {
            string plainText = "=2/";
            char[] chars = new char[plainText.Length];
            string key = "=2/3E*45-`~6<>!,.7+8[]9|:0";

            for (int i = 0; i < plainText.Length; i++)
            {
                if (plainText[i] == ' ')
                {
                    chars[i] = ' ';
                }
                else
                {
                    int j = plainText[i] - 97;
                    chars[i] = key[j];
                }
                string val = chars.ToString();
                string par = chars.ToString();
                Type classtype = Type.GetType("English");

                object test = logic.Convert(val, classtype, par, current);
                test.ToString();
                if (test != "=2/")
                {
                    throw new Exception("fail");
                }
            }
        }
    }
}

Below is my base code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication3
{
    // View with no code-behind
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }

    // From plain to encripted Text
    public class EncryptConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter,
                System.Globalization.CultureInfo culture)
        {
            string plainText = (string)value;
            char[] chars = new char[plainText.Length];
            string key = "=2/3E*45-`~6<>!,.7+8[]9|:0";
            string recrypt = "abcdefghijklmnopqrstuvwxyz";

            for (int i = 0; i < plainText.Length; i++)
            {
                if (plainText[i] == ' ')
                {
                    chars[i] = ' ';
                }
                else
                {
                    int j = plainText[i] - 97;
                    chars[i] = key[j];
                }
            }
            return new string(chars);
        }

        public object ConvertBack(object value, Type targetType, object parameter,
                System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

    // From encripted to plain Text
    public class DecryptConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter,
                System.Globalization.CultureInfo culture)
        {
            string decodeText = (string)value;
            char[] chars = new char[decodeText.Length];
            string key = "=2/3E*45-`~6<>!,.7+8[]9|:0";

            for (int i = 0; i < decodeText.Length; i++)
            {
                if (decodeText[i] == ' ')
                {
                    chars[i] = ' ';
                }
                else
                {
                    int j = key.IndexOf(decodeText[i]) + 97;
                    chars[i] = (char)j;
                }
            }

            return new string(chars);
        }

        public object ConvertBack(object value, Type targetType, object parameter,
                System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}