'99 non-regen - burny-resistor diagnosis help, please?

[808Pants]

My ('99) remains sadly underutilized but I try to keep up with the basics, eg auto-charging. I noticed recently that my post-charge voltage was down considerably, and in poking around (really not at that point interested in cart troubleshooting) noticed that the power resistor on the solenoid was too hot to touch, despite key being off, etc. It was becoming discolored from overheating. By a fairly mindless trial-and-error method, I disconnected leads from the solenoid to see where the resistor-overloading might be coming from; it was via the yellow lead to the controller. As I was disconnecting the yellow lead from the controller, but before it was really loose, there was a pronounced 'clunk' at intervals of maybe 5-10 seconds coming from within the controller (not just from my disconnection effort). Sounded louder than I'd expect a relay to be, so it made me nervous.

Other maybe-useful data include that it's often REALLY wet/humid here, and for a time, the access-cover over controller/solenoid was missing, allowing the solenoid and controller to get hit indirectly by rain - but I think they're fairly well sealed up against such concerns, yes?

Anyway, after disconnecting the yellow lead, it seems to charge more or less normally...but what's the likely culprit?

I've not tried moving it under its own power for months (was OK back then) and don't really want to do so now for fear of truly smoking something that's actually still OK.