Volkswagen: 1988 volkswagen cabriolet gas engine, volkswagen cabriolet, fuel pump relay

Question
Rick O, My V.W. just stopped running .  The fuel pump does not seem to be woking. Checked fuses and by passed relay, but still no power back to pump.  Radiator fan has been giving me trouble also. Works only with defroster on , however now does not work. I changed switch at bottom of radiator and still did not work. Could there be some other electrical problem causing the fuel pump and fan not to work. Thanks, Glenn

Answer
Glenn,
  On this model/year, the fuel pump works by sending 12VDC from: Battery -> Ignition switch -> fuel pump relay -> fuse S5 -> fuel pump.
Troubleshooting:
With ignition on, pull S5 and check for 12VDC on one side.  If there is voltage, the fuse is bad, the fuel pump is bad, or the pump ground is bad.
If there is no voltage at the fuse, pull the relay (the second relay above fuses 5 and 6), test the large contacts for 12VDC.  Only one should have voltage.  If so, the relay is bad, or the signal from the ignition switch is missing.  If there is no voltage on either large contact, there is a wiring disconnect back to the battery (which could be affecting the radiator fan circuit.)

Rick