On the bulkhead connector, blast it with baking soda, just the common food store stuff, before you remove it, it will clean the connectors, you will thank me later, when your wiring has a clean connection.
Tractor supply sells a hand held QT blaster for like $20, dump a box of store brand baking soda in it, and it will literally polish the connectors.
This is a set of emblems off my grandpas farm tractor, that my uncle restored.
He said he could not get the trim bright, 10 seconds with a cheap blaster, and 50 cents worth of soda. Before and after, you decide.
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