On the windows Id lube anything that moved with some white lithium grease to see if it helped before tearing into mechanicals.  Since both door locks are dead it may be the power to the entire lock system but Ive had trouble in the past with the door connectors.  I pulled the connectors off of the swith back on the door panels and used a wire brush to remove corrosion  from the male part of the connector and contact cleaner on the connector plug.  Ive also had to "rebuild" the female part on mydrivers door by taking it apart and resoldering the wires  then reassembling the plastic connector.  If I remembre correctly, a bad connector on one door killed both locks... but its been a while.