My money's firmly on the connector block under the tank. If it happens again try moving the bars firmly from side to side. This puts pressure on that block and can make things work at least intermittently. The quick fix for that is to bridge the block with one (if you can identify which one) wire or all wires. If you can find a burnt, even slightly brown, terminal inside the block, that's your culprit. My quick fix has become a permanent fixture........
I also suggest you wear your engineers cap while doing this. Looking badass is important when trying to fix electrical issues.