Blue/red Wire. Instrument Cluster Back Light.

Last week, my instrument cluster light went out, so I pulled apart my dash today to see. Took out my test light and checked all the fuses, and the 5 amp fuse wasn't lighting up, switched the fuse out and nothing. Tried it with the key on/off, lights turned on/off, still nothing. I followed the blue/red wire on the back of the fuse box and I cant really see where its going under the dash, but i see it connects to the back of the instrument cluster, and the headlight switch. I know it has something to do with that wire, just not sure on how to approach this with the dash in the way. Not to mention its tangled in the 100 other wires behind the fuse box. I've tried looking at wiring diagrams, but doesn't show much about it. Any one got an idea on what to do?

Also does anyone know the name of the rod that goes in this?
https://lmr.com/item/LRS-50600A/83-93-Mustang-Hydraulic-Cylinder-For-Convertible-Top

Was looking more into it, and it also goes to the cigarette lighter light, which won't turn on either.

I see the blue/red wire behind the radio, but it was taped off? The fuse isn't blowing and all the wires on the back of the headlight switch are working except the blue/red wire. The only thing I can think of is the ground is bad, but I'm not too sure where the ground is?

If it helps I also have the white face gauges not the stock ones. The wiring taps into the blue/red wire behind the headlight switch and a ground wire that also connects to the headlight switch.

Ended up connecting the power wire to that brown one. Thanks for the help jrichker.