Now, all we need is a good ole ammeter.
Since 1955, many manufacturers have dropped the good old ammeter. I am thankful my '85 Volvo has a voltmeter. That is better than nothing, but I really like an ammeter, because it will always point out problems with your charging system, hopefully before you get the red light of death.
Not so my wife and I, on the road in 1994, where out of the blue, our venerable 85 500SEL flat-ass died on the Interstate. I usually carry a toolkit with me, but did I have a clue as to what was wrong? I had no indication of a problem before it quit. I felt like a fool. I tried to restart it. Nothing. I cleaned the already clean battery terminals, no rats had chewed through the cables, so I was at a loss. We waited about 15 minutes, then tried again. The mutha started! Still no clue from the idiot light.
We got to the next town and I bought a battery. We figured it decided to die (intermittently). Wrong. One hundred miles from home, it acted up again, this time while starting it after getting gas. This time, I had time to find an automotive electrical shop.
The shopowner knew right away what the problem was. He pulled out what was left of the brushes from the alternator, found a set that fit, and we were on our way again.
I have never seen a better example of what I would consider a major flaw in a manufacturer's instrumentation scheme before or since. That $^#$% idiot light never did light up, although the alternator must have been putting out zero amperes.
You electrically-adept guys can slap me on the wrist if I am wrong about this.
I was supremely disappointed in 1955, when the major auto manufacturers began putting idiot lights in place of the always critical gauges for oil pressure, charging rate, and sometimes even temperature!
Not satisfied with slapping we auto enthusiasts in the face, the fancy-dancy stylists did not even leave us enough room on the dash to insert the now-missing instruments, we had to hang them off the bottom of the dash, where our significant others would snag their panty-hose!
Double-trouble! Now not only did we have to look down and to the right to see if everything was still OK, every time our honey wanted to get closer, she skinned her shins on those &%^$# out of place gauges. Shades of 'discouraging words'!