If you didn't already know, you DO NOT have to cut wires to change the connectors. Just release the OEM wires from the connector and pop them into the new one in the correct sockets.
Go ahead and try another spark plug cap too. They're ~4k ohms. A search like ATC200ES spark plug cap on Ebay will pull some up. Choose one of the NGK ones. Caps are pretty generic for these, so you don't have to overthink it. Most of the time when they go bad, the trike just won't run, but I certainly wouldn't rule out some left field problems.
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