also check your wires and terminal ends for tightness and "green death". [the corrosion that can grow into wires from not having tight and moisture proof terminal ends]
do a voltage drop test when cold, then when hot. [watch your pinkies when around headers that are hot !]
i like to use marine grade shrink tubing with the glue that seals the terminal connection.
also make sure the wires are large enough to carry the current. i have seen some imported wire [insert your country of choice here] that claimed to be "xx" gauge size, and looked the part, only to find out the insulation was thicker, which made the wire gauge smaller than claimed.
and speaking of insulation, get a quality wire with the correct automotive grade insulation. [of course i forget the name of it at this moment !] a lot of wire on the market today has inferior insulation, not really meant for the heat and vibration of vehicle use. [again, insert the country of your choice here]