What is the pink wire in trunk wiring to tail lights

Had the running lights on while I tried to figure out why one of the bulbs wasn’t working and got a strong burning smell and very hot by drivers side of trunk. After undoing what I think is the original harness wrapping I traced the smell to a pink wire. It is thicker than the others and has “Do not cut or splice” printed on it. Would it be a resistance wire? I could not find this in the wiring diagram manual (but am really bad at reading schematics). Lights do still work including brake lights and turn signals.

Any help is greatly appreciated


It is a resistance wire. Usually doesn’t get hot unless you have put in different tail light bulbs or you have a short in the wiring to the bulbs.

It is a .75 ohm resistance wire that is used to decrease the intensity of the running lights. With 6 bulbs @ 14V, it will dissipate about 10 W - this will cause the wire to get very warm!
But the heat is distributed over the 34"-35" length of wire.
It’s possible that the wire insulation has deteriorated over the years and is causing the smell.

I had no idea they used a resistance wire in series with the parking lights. I don’t see that in my 70 schematic either. Where is it physically located?