It is not really a regulater. It's called a constant votage unit. It has a pulsed output. THe output should fluctuate from zero to 6-7 volts. THey do fail, but I have rarely encountered one that was actually bad. It needs a good ground, 12v in on one of the terminals, and a pulsed output on the other terminal. But if it's failed, you can construct a simple voltage regulater to put out about 7 volts, it should work. If you make it adjustable, you can fine tune the gauges to be accurate.