The white-brown contacts provide (via the brown wire) +12V power to the lights, horn, brake lights, and the coil of the starter relay. 2.3 Ω is quite high , did thet measurement "include" the corroded connector?
A modest 2 A load through that 2.3 Ω resistance would produce a 4.6 V voltage drop--leaving just 8.0 V (of a fully charged battery's 12.6 V) to "do the job".
Obviously the corroded terminal needs to be replaced. In doing so make sure the wire is clean and shiny, and use some dielectric grease (SuperLube's PTFE grease is very good for this)--$6. at Home Depot--to "pot" then connection. Make sure you use a good crimping tool also, like this "full compression" tool from HF:
This tool will create very reliable connections unlike those tools that just "squash" the terminal ferrule.
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I suspect your recent manipulations of the wiring disturbed some poor connections and made them conduct. This is not uncommon, in emergency situations it can be, and has been for many, a viable action to get going again,,,