66 c10 electrical/cluster q's

[msg]

I was hoping to fix the cluster on my 66, but do not have alot of electrical experience.

Here is whats going on.

What are the best ways to fix these?

speedometer= does not work

temp = just stays at Cold

battery = stays in the middle even when disconnected

oil = it seems to work, when running the needle goes mid way

fuel= kinda works. when full it goes to F and then as I get around a half tank it moves quickly back and forth the whole time. I checked to see if the wiring to the fuel tank was maybe touching the chassis and grounding out but throughout the length of the wire didnt see any exposed wire.

The Tandem Lock light = stays on all the time. I recall the guy I bought it from telling me that that light should go out when the engine is revved up and that if it didnt the battery would run down. It has cut off in the past but recently it just stays on. Should I just pull the bulb from it?

I was wanting to add a tach and vacuum to the cluster but figured all the other gauges should operate correctly first.

Anybody have suggestions on how to get this all working right?