I agree, the 3 pin thing is called a voltage regulator. It regulated the voltage to the temp and fuel gauges, at about 10 volts. The old KE30's did not have this as the gauges themselves had a bi-metal regulator (or maybe I am thinking RA23). But the latter KE55 had the solid state voltage regulator. Yes, they burn out sometimes, but sometimes the contacts are just bad. Try soldering the joins rather than just using the screw on thing.