[projectRDM]

For the window, is your car a 95?

The 95 S14s used an external window amp instead of an internal one in the switch. The switch itself is common to break or wear on the auto function, so it feels loose, what's happened it is it's broken inside and making contact irregularly, when trying to roll it up it's also feeding a down input, alternately the switch will stick sometimes when rolling down and keep power on the motor after it's down, eventually burning up the motor. They changed the design on the 96-up because of that. Every S14 I've parted out, the driverside window switch is the second most sought after part. What I'd recommend to solve it permanently is to switch over to 96-98 electronics, all you need is the switch and the door harness, easily found in a salvage car. The rest of the wiring for the passenger side is the same and the newer door harness is a direct plug in, and you'll never have to worry about it again. Buying a new 95 main switch will only postpone further problems.

The speedometer could be a damaged VSS, if the pinion gear is broken or teeth have sheared off it will erraticly jump like that, otherwise the gauge itself is bad. It's not likely a ground problem because you'd see problems with the entire cluster, not just one unit.

The cluster bulb is more than likely just loose, try twisting it in tighter to make a good contact.