Gray / Yellow Wire under Driver Side Dash

[oleskool]

Does anyone know what this wire is for under the dash of my 89’ 4.0?  It appears to be spliced and poorly soldered to something else in the harness. Trying to figure out what it is before I start messing with it. Appears to be a fairly heavy gauge which makes this even more concerning 😂 

[Ωhm]

If it a factory wire and if it could have been VIO/YEL at one time, it the Blower Motor Feed for the AC or Heater control unit.