By cluster lights, I am assuming that you mean the lights that illuminate the gauges - called dash lights in the service manual. If so, the dash lights and your mirror switch light (just the light, not the mirror motors) and a whole bunch of other lights get power via the taillight relay and then through fuse
#18 .
Get the service manual (there is a link to free versions of the shop manual in the red bar at the top of the Prime web page). In the electrical section of the manual look at the section under the headings
dash light brightness control and
lighting system. On the wiring diagrams, you should find a list of all the other things that get powered up by the taillight relay. If all of these lights are flickering at the same time, chances are that the tail light relay is failing, or you have a bad connection to the
#18 fuse or the relay (check for a burned / loose socket). The tail light relay gets its power on signal from the head light control switch on the steering stalk. It is also possible that the headlight switch is failing / has dirty contacts or that there is a bad connection between the headlight switch and the tail light relay. Finally, there may be a bad connection between the
#18 fuse and the dash lights and other stuff.
I would check the relay and fuse first just because it is the easiest to get to. I would then check the operation of the headlight switch because it is the 2nd easiest thing to get to. If all of that checks out good then you likely have a loose connection somewhere. The wiring goes all over the place so you really need the electrical section of the shop manual in order to trace the harness(s) and find all the connectors that are in the wiring path. That involves some serious dumpster diving under the hood and under the dash. Good luck with that - take two aspirin and don't call me in the morning!
