High Beam on dash not working

[67mag]

Howdy folks!
I have run into a strange situation where when I click on my hight beams my dash bulb will not light up. I have the cluster out at the moment and am about to swap the switch and floor dimmer switch, I have turn signals but there are two other sockets one being the HB socket and the other the lamps not locked bulb. I cant remember which is which so will have to check the diagram. Has anyone else ever ran into this issue?
Thanks!
Dave

 

[Belchfire 5000]

On my 66 the HB bulb is under the headlight locked bulb.

 

[67mag]

Thanks a bundle! I am going to test the sockets today after swapping out the light switch and dimmer