First let me say that I believe this is a technical question, but if not, I apologize to the moderators and please move this to the general discussion section.

With that said, I was driving into work this morning and went to adjust the instrument panel brightness in my 88 GT. Everything was working and as soon as I moved the panel dimmer switch ****, everything went out. So I am thinking the switch is bad and just needs to be replaced. Can anyone confirm this as the most likely cause of my issue?

 

Yes, it is probably the dimmer switch. The contacts tend to wear out over time. If you buy a new one from Ford, it is made out of cheap black plastic (the originals were made out of pot metal) and is of a different design. It's gonna cost you around $70 too. You also have to transfer the "Dimmer" sticker off of the old unit onto the new unit.

I would get one out of a junkyard or off of Ebay.