On 1300 cars (at least) there is a plug between the alternator harness and the main loom that includes the main charge wire. I frequently find signs that the connector for the main charge wire has gotten hot enough to discolor the plug. In many cases the alternator light glows faintly under heavy electrical load, even if the connector is not discolored. I believe that the charge wire was sized for the early alternators, and is too small for use with larger capacity alternators.
Therefore, I add an additional 10 gauge (or larger) wire between the alternator and the starter. I typically don't install a connector in that wire, so you wind up having to remove the nut on the back of the alternator to disconnect it, but at least it removes that point of resistance. That solves both the overheating of the original connector and the slight glow to the alternator light. It also makes a noticeable difference under heavy load. I don't recall seeing it mentioned here before (except by me), but I consider it a must-do electrical mod for Xs, as well as some other cars from that era.
