[linearB]

I did some mechanical work this year (new chain, sprockets, brakes -- stuff I was overdue for), and now I'm having an electrical problem 

The behavior is that the bike will fire up, run for some period of time, and then I will lose power and have a blown fuse. I am fairly certain it's the fuse on the circuit with the fuel pump on it, because when the fuse is blown, the lights/etc all work but I do not hear the pump spin up when I press ignition, and the ignition will therefore go chuggachuggachugga without firing up.

Electrical problems are not my forte, at all. Am I correct in thinking that this sounds like it's either a bad pump or a bad relay to the pump? Are there any other potential causes I should be aware of?

What troubleshooting steps should I take?

One bit of backstory -- when I first got this bike (used in 2012, with 5000 miles on it), I very quickly developed a problem where the fuel pump would flake out. In that case, I traced it down to a bad connector plug between the fuel pump and the wiring harness; I cut the plug out, connected those wires directly with screw-on caps, and it was fine for quite a while. I'm not sure if that's in any way related; I've re-checked the wiring job I did there, and as far as I can tell everything is still well insulated, separated, and I do not see any way that it would just be shorting out at the level of the screw-on caps I installed.

It seems to me that this problem initially would only occur after the bike got really wet, but now it's more universal and unpredictable.

One final note: at one point I had replaced this fuse with a slow-blow 20A fuse instead of a standard 20A; that provoked scarier behavior, in that the engine light was flashing on and off when the keys were turned. It did not seem to me that there was an obvious pattern to the blinking, it was just long on, off, long on, off. But, if it would be useful I can put another slow-blow on there and see if I can reproduce that and better document the blink pattern when I'm not, you know, riding down the road.