88 xj gauge lights not working

My spedo and my fuel gauges lights won't turn on. I pulled the cluster and all the bulbs are good. Other lights work like battery and oil pressure signals ect. Just not spedo and fuel. Anybody know why?

Do you have your headlight rheostat turned all the way down??

Best guess is you broke the tiny tabs off the back of the bulb holder and it isn't seating properly and is not making good contact. On my Renix (all three) I've rarely been able to change a bulb and not break the the tabs off the bulb holder. My solution is to push the bulb holder up tight and put a couple of tiny drops of super glue on there to hold it in place. I use a toothpick and the tiniest drop of glue, so I can break the glue bond the next time I need a bulb and then re glue it in there again.

The orange/black wire is the power to the instrument bulbs. You have a single power source (dimmer in the headlight switch) for four different pins on the cluster connector. Maybe one of the pins is making poor contact and that is the pin for the speedo and fuel gauge bulbs?

I spray out the connector with contact cleaner, then clean the contact strip with a clean pencil eraser (the coarse ink type eraser actually works better) and then wipe down the end of the contact strip with a quality contact cleaner. There is a TSB about corrosion on the contact strip for the cluster.

in addition to that I like to take a small pick and "pluck" the contacts up slightly.
Don't get wild or you'll break them, but you can bend them up so they make better contact.