Camera render to texture, draw on GUI?

So I'm faced with the task of implementing a minimap in my game.

I have a secondary camera "camera" in ortographic mode, positioned in the center of my terrain, pointing straight down.

I then created a texture in my assets, and told the camera to render to that texture. Then, in my "Main Camera", I have a "minimap" script which has a property 'texture', I drag'n'dropped the texture that the secondary camera is rendering to, into that slot in the editor. The script is as follows:

 using UnityEngine;
 using System.Collections;
 
 public class Minimap : MonoBehaviour {
 
     public RenderTexture texture;
     public Rect position = new Rect(0, 0, 400, 240);
 
     // Use this for initialization
     void Start () {
 
     }
 
     void OnGUI() {
     //doesn't work :(
         GUI.DrawTexture(position, texture);
     }
     
     // Update is called once per frame
     void Update () {
         
     }
 }
 

And... nothing. No errors but still nothing is being drawn. What am I missing?

Thanks in advance.