MetalEd

a while ago I asked a question about how a previous owner had wired my electronics (direct to battery) and left a couple burned out radios and other electronics in the trunk. I was running a Timing Light (powered directly by the battery), it worked fine at idle, but burned out at Hi-RPM..
Today I was reading the instruction on an aftermarket tachometer. It says it must be directly connected to the "Pink Resistor Wire" under my dash or a 1.4/1.8 ballast resistor if bypassing it.
I have the "pink resistor wire" in my dash since I have the early 1964 Generator wired mustang. My question is this.... could those electronics and my timing light have burned out because they were not connected through the "resistor wire"? The prior owner just ran wires direct to the battery to the new electronics under the dash and my timing light was hooked straight to the battery. So maybe high RPMs created more electricity and burned them out? (still trying to figure out if the Generator has been upgraded to an alternator.)
Wouldn't all add-on electronics have to be run through the resistor wire or a separate ballast resistor if connected direct to the battery to protect them from too much voltage? Or is it just for the coil (why the tach. Connection)
Maybe a Generator Voltage Regulator hen it needs to be a Alternator Voltage Regulator?
I'm not exactly sure what a "resistor wire" does.
Any insight is appreciated!