Matt, I like Drambuie with my Scotch - it's called a Rusty Nail!

I'd pull all wheel drums and check the wheel cylinders and master cylinder for any signs of brake fluid residue. It is conceivable that the downhill parking may have siphoned air into a leaking rear wheel cylinder, then spilled out enough brake fluid to appear as if all is well. You did say you added brake fluid, so there's a leak somewhere. Regardless, I'd check the entire system and bleed the brakes before driving your Amazon. It may be advisable to replace the old brake fluid since it likely is contaminated with moisture that will cause problems next winter for sure.

Regarding the electrical system, I'm afraid you'll have to check all connections. I've experienced weird electrical problems, known as a "ground fault", especially on a Lucas equipped 1800-S. As recommended, clean all visible contacts and inspect the wiring harness for any fried wires as well. It's a dirty job, but someone has to do it. Can you imagine paying a garage $90 and hour to find this fault? Not me. Think I'll have another Rusty Nail! Good luck
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Cam a.k.a. CVOLVO.COM