pink resistor wire? resides where? 1 wire alt upgrade recommendation?

[67resto-coupe]

since i've been having issues getting my '67 coupe to run consistently, i've rebuilt the carb, installed a new tank and thought i was on my way to cruising bliss.  but then my car died several times on a cruise around the 'hood.  a local mustang shop asked if my coil/dist was getting a full 12v connection.  i don't know.  i think so.   how could i check?  i borrowed a meter thingy.  the shop told me to look for a pink resistor wire, but in following my + coil terminal, i could only find a red wire w/a green stripe.  that goes all the way to a pigtail coming out of the firewall and it joins to another red/green wire, no pink. 

is this phantom pink wire under the dash only?  is there a way i can use the meter to check the voltage going thru the line?  i guess i could stab the pigtail coming out and touch the + terminal?  i don't want to fry anything, so your help is appreciated. 

maybe my alternator is dead?  any tips on brand?  amp output 100 or 140? 

thanks.

[jims6t6]

it's under the dash close to the ign switch

[Midlife]

Rather than trying to trace wires, why not put the key in RUN and measure the voltage at the coil?  It will either read about 9 or 12V (with or without the resistor wire) or 0 if it happens to be in a certain location of the distributor.  If so, simply turn the engine a bit.

Or run the engine and measure voltage...