Wurth Contact OL is a pricey but very effective spray on solvent that
improves the conductivity of corroded connectors.  I bought a can at a
local VW dealer a few years ago for around $9 a can.  The parts man said
the Alfa Romeo (sp?) service technicians used to be regular customers.
They used it to eliminate the electrical gremlins common in the cars.

I use it now on all my cars any time I work with electrical connections.
It was very effective in solving the Vanagon turn/stop/taillight random
dropout syndrome.  I just used it on the two chassis ground terminal
assemblies that are hidden above the main fuse block to brighten the
headlights on my 83.5.  One female spade connector on a ground wire was
broken and just hanging on by one side so I replaced it while there.  I
sprayed each connector and worked them on and off a few times to cut
through the oxide layers.  For any loose connectors I gently crimped the
female end until it fit snug on the spade terminal.

Bill
83.5 Westy