OK lets get this Runtz thing straight: This device will not be the source of a gauge problem. It's a great way to use your original gas gauge on 12V.
1. I believe it is a linear Voltage regulator with overload protection. A fuse would also protect the gauge further.
2. Assuming it is a linear Voltage regulator using a TO-220 package as I said, the whole advantage is that these can take any unsteady/unregulated voltage, in the case of a true Runtz, 8V to 28V and give steady output, in the case of Runtz...7.5V, Steady, as in: steady.
There is no voltage spike sent into the electrical system by the starter or solenoid.
3. I don't know the facts or knowledge behind anyone who says they "fail", "don't work", burn up or whatever.
4. The Runtz is used by many gauge rebuilders and sold by well known vendors. As I said, there are knock offs, there are people who call anything a "Runtz". I don't even know if someone like Speedway Auto, who sells Runtz, knows what they are saying. They use the word Runtz in quotations "Runtz". I'm afraid the word has morphed into meaning a reducer. The Chinese copies could be called Runtz by some companies not realizing it's a Brand name. Not sure. We all say Kleenex, Band Aid, Coke...those are Brand names that have become nouns.
5. A resistor will work, albeit not as accurate. The gauge can be protected by a simple inline fuse before or after the resistor. Wherever a person thinks is best.
6. The "Runtz Voltage Drop" was invented by the owner of Fifthave, Randy Rundle, with help from his friend Dan Schulz in 1992. They combined their names and got the word Runtz.
7. Randy passed away Feb 1, 2021.
TO 220. Not sure if he used this or not but I think that is what is under the shrink sleeving.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
