I have a 1973 mustang and my instrument cluster lights don't work. They worked (very dim) when I first bought it. Since then we have installed a speaker wire under the dash but not up by the cluster harness. I have checked all the fuses and they check out good. Are there any in line fuses or fusible links that might feed the cluster. All off my other lights work. I do have a 73 wiring manual diagram and on page 5 it shows a f-5 protecting wire#19 LB-R. Is there another fuse block?

Thanks