Just throwing my two cents in but any signs of rodents getting in seen that a bunch also check grounds dont condem a module untill you have tested every circuit unplug each circuit from both ends and only do this if ur 100 percent sure you have both ends disconnected u can then apply 12v to the circuit see if it lights a tail light bulb if not replace that circuit again I would not do this with out a wiring diagram u can blow a module if this is done incorrectly basically ur looking to see if the wire itself can sustain enough current threw it ran into wires that were mostly broken internally doing a ohm check will say it's fine when it's not make sure u have continuity with ur meter on both sides of a circuit after u have disconnected it