Dear MorganM,

Hope you're well. Further to j.pelchat's excellent points, I suggest use of an aerosol electrical contact cleaner (e.g., DeOxit or similar). The reasons: (a) an invisibly-thin layer of corrosion can disrupt a circuit (things can look fine, but aren't); (b) it is very hard to clean the contacts inside connectors with steel wool or fine sandpaper, but a spray will reach and clean those.

On connectors in the engine bay (or other exterior areas) a thin coating of di-electric (tune-up) grease on the connectors' metal contacts will keep humidity away from cleaned contacts and so slow renewed corrosion.

If You've not done so, replace all working fluids (coolant, oil, brake fluid, automatic transmission fluid and differential oil). This site's FAQs (upper left) provide guidance as to the doing of these things.

Hope this helps.

Yours faithfully,

Spook