Bump map isn't working

I am doing a tutorial here: https://www.youtube.com/watch?v=td9QXLHtoJ4&list=PLBbfFcNW4C9fTv2N6A4mKwSCLDoPCsU5W&index=14 He uses an add-on to add texture to the jeep. I am unable to get the texture mask to make the jeep’s body appear as though the dirty spots have a 3d look to them as shown in the tutorial. All I get is black. I was able to get it to work yesterday, but I must have done something so now it doesn’t work. Can someone tell me what I am doing wrong?

From the tutorial:

This is what I get:

Blend file: http://www.pasteall.org/blend/33091

You have not included the bump map in your blend file. Did you save the texture before packing into your blend file ?

Yea, have to save the images on the disk before packing. But won’t be needed, it’s not showing up because texture paint slot is set to paint on the diffuse layer instead of the bump map image. Texture paint slots are on the tool shelf, second tab from top.

Thanks for responding. I was having trouble keeping my gray normal map gray in the uv image editor. It would turn black if I changed the mode in the 3d window. I wonder if it was because I wasn’t saving the gray bump map as an image.

I found the paint slot. I’m good for now.

You always need to save the bump at 50% gray on disk so that when you revert with Alt-R, it doesn’t go back to default black