Have some Lights, but not others, Help!

OK with the cluster out, there is no ground to the cluster, so of course it will measure "some voltage." The cluster must be grounded to properly operate. If you are getting some lights with the cluster "out" that is a wrong road you are traveling. You've created a feedback/ loop/ etc

The gauges, except ammeter, are powered from a sort of regulator, variously referred to as an IVR, instrument voltage limiter, instrument regulator, etc. It's a small rectangular box, plugs into the rear of the cluster. If you read the thread I posted, it mentions fixing the board where that fits. The harness connector on the board is troublesom

The dash lights are a "trick." There are TWO power supplies to the headlight switch. One large feed, NOT FUSED comes off the ammeter circuit, and there's a breaker on/ in the light switch. This feed powers ONLY the headlights

The tail /park circuit is fed off a fuse which is hot at all times, so you need to see if you are even getting that power to the light switch.

The dash dimmer control (twist the knob) ALSO gets power off the above tail / park circuit. The output from the dimmer then feeds TO the fuse panel "inst" fuse-----on one end of the fuse panel.......so that fuse won't show power unless.........

The tail circuit is getting power from the fuse supplying it..........the light switch is in park or head..........and the dimmer control is twisted "some" left

Then that dimmer controlled power goes through the inst fuse and supplies all the dash lights through ORANGE wiring. If you see an orange wire under the dash.......radio.....ash tray.......heater controls......cluster.......that is dash dimmer controlled power