Having much experience getting rid of asphalt-like material off of wires, I'd recommend the following solvents in order of ease:
Gasoline
lacquer thinner
Goof-off (never got it to work effectively)
Gasoline and lacquer thinner will require elbow grease, and gas will loosen the crud up easier than LT. No need to worry about the wire insulation or washing off of the wire colors (the fuel sending line past the trunk drop-off is the only wire that consistently appears to be painted on!).
I've never tried HD Easy Off Oven Cleaner with lye, but I suspect it will work pretty well in a well-ventilated area.