Electrical problems are often the most difficult to diagnose. Preventing them in the first place is a great way to not have to spend time later doing diagnosis. How to do that? Well, one way is to wire the car to OEM or if you are even more hard core, to motorsports specs.
Now, the InfinityWire system is already an OEM-quality system. But if you modify it, it's nice to know how to do that part correctly.
Likewise, if you are racing, there are strategies that, while they cost more in the beginning, pay dividends in reliability- and chances to win races instead of sitting in the pits with multimeter leads flying everywhere trying to figure out a problem on a hot engine!
There is a pretty good primer on wiring cars for motorsports from RB Racing here.