The Runtz has a built In circuit protector (think time delay fuse) so in the event of a short in the wiring harness caused by a bare wire, or a pinched wire, or some other defect, the Runtz will protect your gauge. You gas gauge runs on about a 1/4 of an amp, the Runtz will act like a fuse when anything over 1 amp makes it way to you gauge.
In this case you could have destroyed the Runtz as a result of the short in the wiring harness. That is of course better than destroying your gas gauge. I would try and find out what caused the short in the first place. Usually it is a place where the insulation has fallen off or a wire has gotten pinched. Once you have fixed that, check the Runtz it should have about 7.85 volts on the output side. If it has zero output you can simply replace the Runtz and you will be back in business.
Also...it works best to power your ignition switch with power directly from the battery. Simply run a 10 gauge wire from the positive post of the battery to the ignition switch, Many modern battery cables have this wire already there.
The reason for this is to prevent voltage spikes. When the contact points inside of the starter solenoid close, or in the case of the foot starter button, when that contact is made a voltage spike is created. It is about 300 volts!!! It does not last long, just a mega second but it is enough to destroy solid state accessories like a modern radio (you will see the led numbers go away first) or things like cell phones plugged into cigerette lighters (you will send your startac back to the homeland) and a Runtz on a rare occasion, or the fuse to the ignition switch.
If the power to the ignition switch comes from the battery the battery will absorb all of the voltage spikes. You should have what the engineer types refer to as clean electricity, which will prevent future social embarrasment and disgrace.
Thanks, Randy
