Dear V-8 Buick electricians, There is a new series on the Hagerty’s website about electrical troubleshooting your classic. The first piece is on how a short-circuit can literally burn your classic to the ground: https://www.hagerty.com/articles-videos/Articles/2017/05/23/short-circuit-danger The author, Rob Siegel, makes a very helpful attempt to explain how electricity works and tries to explain the mathematics in a way that is understandable. However, if you find the math a little too heady for your tastes, skip to the punch line were Rob points out that the power released during a typical short-circuit in a car is around 14,400 watts!! Now what 14,400 watts of power actually represents is a little hard to comprehend. Imagine the heat of around 10 toaster ovens all in one wire and that gives you a better idea of the power coming out as heat. Another way to think about this which is more "car guy" is to convert the power released into horsepower. 1 horsepower is 745.7 watts of power. If you do the math, a short circuit is releasing in heat a little over 19 horsepower!! That’s the sort of power you find in riding lawn mowers! Of course, one doesn't normally use horsepower to represent thermal power, but it gives you some idea of the amount of energy per unit time pouring out of those short-circuited wires! Now obviously that amount of power being released in a wire will destroy the wire very quickly - thereby breaking the short-circuit. Alas, releasing that amount of thermal energy in the tight confines of your engine bay is very likely ignite something else and get a fire going that would be extremely difficult to put out. So if you were looking for a good excuse to double-check your Buick’s wiring - I think this qualifies! Cheers, Edouard
That is why the car designers include fusible links in the main power feeds. Fuses protect individual circuits, but fusible links protect the entire car.
Fusibile links were not a part of the older harnesses (early 60's and older). I've seen a bunch of fried engine and dash harnesses in the last couple years. There was a "fix" to this that was basically a fuse that was attached to the voltage regulator terminal in-line of the main power feed. The short would fry the dash harness because all switched power went through the headlight switch, for some insane reason. See image below - it is attached to the BAT terminal on the regulator.
