Just a word about a problem I had just before Christmas. Came out one morning and discovered battery totally flat (2.5Volts). Battery charged and reconnected. The fan motor began to run even though the engine was cold. Fault traced to two wires going to fan motor at botom of the rad. Red and Blue wires had been in contact probably since manufacture and insulation had eventually rubbed through. Cured by seperating wires and reinsulating. Anyone with 2005 Octavia should check next time they do a service. The wires are easily accessed when you take off the cover under the engine. On the road again. 110,000 Km so far.

Edited 5 January, 201016 yr by PGbriskoda

Similar problem on my Octavia mk1 1.6. The battery was completely flat so I recharged it and found that both fans are constantly running even when key is removed from the ignition. Unable to locate any damage to cables so not realy sure why they are both running. They both seem to be connected in parallel so the wiring should be independent of each other. I am guessing that there is a relay or switch somewhere that controls the two fans. This may be be latched on causing them to run constantly or alternatively I'm wondering if the thermostat is faulty, any ideas?