How do I export vector/speed info to an exr file?

I’m trying to export a scene’s vector info into a file. My nodes are set up like so:

Rendered Layers Speed> Map Value node > Color Ramp node> File output node, saved as multilayer exr.

Can anyone help?

Please, if possible, show us your blend, or a screen-shot of the node window that you are using. Also confirm that the Vector channel is selected in that RenderLayer. (The node window will confirm this. Please be sure these details are clearly visible in your shot.)