smoke from dash

hi there people can anyone help me with a small problem i have with my electrics. a couple of weeks ago the main power cable from the battery to the fuse box burn out right on the join at the fuse box i think it got overpowered as i was running alot of electrics at the time. am i correct? as i replaced the conector and last night i was running my fan full speed and started to smell a burning smell again. could it be that the power cable is to small and cannot handle the overload. cheers people joe
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