Help me behind the dash!!

So, I have been working on geeting some of my dash wiring back to working but have come across a few oddities I could use some help with!

First of all does anyone know what this connector might be? This mysterious V shaped connector with 3 red wires...

Also, is there a way to actually test a voltage limiter? Both fuel and temp guages are dead so I assume it is pooched but would rather not waste 50 bucks if I don't have to (and dread the thought of "building a replacement!)

Third, I have a blue wire with white tracer that is unconnected that seems to be supplying 12v constant (switched at the ignition only) and nothing I switch seems to kill the voltage. Any thoughts what it is supposed to feed?

Thanks in advance,
Dennis