My 1990 Vanagon's radiator fan went on the other day. I had the factory
AC running... air temp outside was around 90 degrees but the water guage
was no where near overheat area. It went into the high speed (very loud)
mode and would not shut down even after the car sat for an hour or more.
It was draining the battery so I had to disconnect one terminal . Even
now, connecting the battery runs the fan in high mode.
I disconnected the 3-pin plug that goes to the dual temp thermostat
switch on the radiator and it still runs. According to what I can
determine. There are two relays. One for the low speed (or speeds as
some say there are two lower speeds) and one for the high speed mode. I
pulled the relay for high speed and it stops. I tested that relay and it
is good. Contacts close when energized and reopen no problem. I assume
this is a standard N.O. relay(?)
I'm stuck. If the fan still runs with the thermostat switch disconnected
and the relay tests good then what gives? Something else is causing that
relay to stay closed. I have no prints of the electrical circuit. Can