FWIW, in my helping friends with various automotive electrical issues over the yrs. with slightly older vehicles with large fuse/breaker/relay boxes located under the hood, being that compartment is environmentally abusive (even though they seem to have a somewhat of sealing latched capable gasketed lid, for longer term less hassle electrical problems, is to initially unplug each of all the plug in fuses, breakers, relays one at a time, then spray their pins & socket contacts with a quality contact cleaner, like CRC, etc. then apply a generous coating of electrical grade silicon grease to the male pins before reinstalling.