I have a 54 plate MK1 Octavia 1.9 tdi I have been having some problems with the air con coming on and off of its own accord now that I have fixed a couple of broken wires to the the fan control module. I now get a problem sometimes where the fan continues to run when the engine is switched off. The fan runs indefinitely in the first case until it flattened the battery. If I disconnect the battery for a few seconds the fan stops and doesn't start again when it is plugged back in.

 

My intended first move would be to swap the fan control module, does this make sense, is there anything else I should try or know about. The Octavia does have climatronic aircon if that makes a difference.

i have this same issue.

i've replaced the temp sensor, control module and also fuse box on the battery as my old one was in poor condition to no avail.

might it be a fault fan switch? i'm kinda thinking thats next on the list, no fault codes are coming up when scanned.

I have just fixed mine with a new fan controller. Also swapped the main fan as the bearings were really noisy.