Weird shader thing

Hi,

I'm making a terrain blending shader that uses 2 blendmaps , for now i'm just testing one. But when i just use:

 o.Albedo = b1;

b1 being the first blendmap it only gives me a solid red like ii only takes the first pixel of the blendmap.

Here's the full shader:

 Shader "Terrain/6lyr_2tex_terrain" {
     Properties
     {
         _blend1 ("Blendmap 1", 2D) = "white" {}
         _blend2 ("Blendmap 2", 2D) = "white" {}
         _Layer1 ("Layer1", 2D) = "white" {}
         _Layer1n ("Layer 1 normal", 2D) = "white" {}
         _Layer2 ("Layer2", 2D) = "white" {}
         _Layer2n ("Layer 2 normal", 2D) = "white" {}
         _Layer3 ("Layer3", 2D) = "white" {}
         _Layer3n ("Layer 3 normal", 2D) = "white" {}
         _Layer4 ("Layer4", 2D) = "white" {}
         _Layer4n ("Layer 4 normal", 2D) = "white" {}
         _Layer5 ("Layer5", 2D) = "white" {}
         _Layer5n ("Layer 5 normal", 2D) = "white" {}
         _Layer6 ("Layer6", 2D) = "white" {}
         _Layer6n ("Layer 6 normal", 2D) = "white" {}
     }
     SubShader
     {
             Tags { "Queue"="Geometry" "RenderType" = "Opaque"}
             
             Cull Back
             CGPROGRAM
             
             #include "UnityCG.cginc"
             #pragma surface surf Standard
             #pragma target 3.0
  
             sampler2D   _blend1;
             sampler2D   _blend2;
             sampler2D   _Layer1;
             sampler2D   _Layer1n;
             sampler2D   _Layer2;
             sampler2D   _Layer2n;
             sampler2D   _Layer3;
             sampler2D   _Layer3n;
             sampler2D   _Layer4;
             sampler2D   _Layer4n;
             sampler2D   _Layer5;
             sampler2D   _Layer5n;
             sampler2D   _Layer6;
             sampler2D   _Layer6n;
 
             struct Input {
                 float2 uv_Blend : TEXCOORD0;
                 float2 uv_Layer1 : TEXCOORD1;
                 float2 uv_Layer2 : TEXCOORD2;
                 float2 uv_Layer3 : TEXCOORD3;
                 float2 uv_Layer4 : TEXCOORD4;
                 float2 uv_Layer5 : TEXCOORD5;
                 float2 uv_Layer6 : TEXCOORD6;
             };
 
             void surf (Input IN, inout SurfaceOutputStandard o) 
             {
                 float4 b1 = tex2D (_blend1, IN.uv_Blend);
                 float4 b2 = tex2D (_blend2, IN.uv_Blend);
                 
                 float4 l1 = tex2D (_Layer1, IN.uv_Layer1);
                 float4 l2 = tex2D (_Layer2, IN.uv_Layer2);
                 float4 l3 = tex2D (_Layer3, IN.uv_Layer3);
                 float3 l1n = UnpackNormal(tex2D (_Layer1n, IN.uv_Layer1));
                 float3 l2n = UnpackNormal(tex2D (_Layer2n, IN.uv_Layer2));
                 float3 l3n = UnpackNormal(tex2D (_Layer3n, IN.uv_Layer3));
                 
                 float4 l4 = tex2D (_Layer4, IN.uv_Layer4);
                 float4 l5 = tex2D (_Layer5, IN.uv_Layer5);
                 float4 l6 = tex2D (_Layer6, IN.uv_Layer6);
                 float3 l4n = UnpackNormal(tex2D (_Layer4n, IN.uv_Layer4));
                 float3 l5n = UnpackNormal(tex2D (_Layer5n, IN.uv_Layer5));
                 float3 l6n = UnpackNormal(tex2D (_Layer6n, IN.uv_Layer6));
                 
                 o.Albedo = l1.rgb * b1.r;
                 o.Albedo += l2.rgb * b1.g;
                 o.Albedo += l3.rgb * b1.b;
                 o.Alpha = 1;
                 
                 o.Normal = (l1n.rgb * b1.r) + (l2n.rgb * b1.g) + (l3n.rgb * b1.b);
                 //o.Albedo = b1;
             }
         ENDCG
     }
     FallBack "Diffuse"
 }

And when trying to blend it only shows the first layer fully, nothing else. Since Unity5 i find that some simple shader things don't work anymore.