I'm not saying that VOM is not required for working on automotive electrics. There are incidents were there is no substitute, voltage to the coil/HEI, from the gen/alt/reg, and the resistance of the sending gas/temp unit. For most of the electrical that I've done on autos I just need to know if I have power or ground. A test light is the quickest and easiest way to do that. Don't have to find a place to set the VOM so you can see it. Don't have to read a scale most of the time it's either 12 volts or it's not, a light tells me that.
Larry