94 jetta no start

best explain is a dead key.turn key and no start on multiple tries.no crank whatsoever.go in to call in late to work go back out to try again and starts right up with strong immediate crank.after driving restarts fine.after a few hours restarts fine.overnight or a shift at work then no start again.replaced battery and does not indicate starter issue.also no wipers.was working fine.now turn on and no response.but then after a few minutes will wipe once.had radio now no radio.sometimes will turn on to safe mode.perform unlock and prior to completing led goes off and no power to radio.no speedo or tach light and no heater control lights.biggest concern is no start please help.........

In addition to checking the cables, check for corrosion.