Gauge Lights don't work!

[CaliCuttie]

First off, my idiot lights come on as soon as the car is started, the turn signal lights come on, the high beam lights come on as well in my instrument cluster, but I can't see a damn thing in the actual gauges like my speedo or tach. I've checked my instrument fuses and they're fine, even tested its fuse in the dome light and that fuse works. What seems to be the problem? For the record, I had a landscape cluster before swapping them for rallies and had the exact same issue. I'm guessing its the wiring, so what exactly would I be checking for then once I pull the gauge cluster back out and how would I fix it.

THANKS!

P.S: The tach has been acting funky as well, the RPMs read anywhere between 1000-2000 RPM's higher than it actually is.
P.P.S: Seems my speedo acts up as well at times, and will click back and forth like a pendulum and gives me a ballpark estimate within a 5mph accuracy. i.e: If i'm going around 50, the speedo will click back and forth between 47-53mph. It has happened a couple of times but eventually goes away

 

[Doober]

Funky lights is likely a bad ground, and on top of that your center gauges (oil/water/fuel) will likely be reading inaccurate. The tachs have a tendency of losing their accuracy, but they're rebuildable (not very cheap though unless you're into desoldering a resistor IC and small capacitor). The speedo/cable could possibly use some lubrication, and make sure the cable isn't binding up, it can cause that bouncing at slower speeds.