My main relay has been failing to run the fuel pump, so I removed, inspected, and repaired the PCB on the main relay. Most of the joints were dry and did not have enough solder. I found some cracks and other abnormalities, so I de-soldered and re-soldered these connections. Here's what I've done, in picture summary,
Documented this because I know others have had this problem. This is a cheap, easy solution if you have the time and know-how.