My -01 Octavia RS is overheating because the radiator fan doesn't run when car is idling, it only starts running at 105 degrees celsisus or so.

I'm going to get a replacement fan, but will also see if i can get a new fan relay because no fans start when AC is turned on.

 

AC probaly has no gas left in it, since it doesn't cool when stationary. 

I have moved around the three fuses on top of the battery and no success, no signs of corrossion or anything.

1. Where is the fan relay located? I can't seem to find it under the battery.

2. Where are the connectors located when looking from above, are the 2 connectors located on the battery-side in the bottom?
3. Besides getting a used fan and relay from salvage yard, what else should i get to minimize time spent troubleshooting...  and money spent...

 

Regards

Consider repairing the low speed function of the fan with an external power resistor, as a salvage yard fan may well have the same problem, if that is the problem.

Radiator fan repair, courtesy of Vortex, here and UK-MKIV forum - Handy Topics & Guides - BRISKODA

 

4 minutes ago, Wino said:

Consider repairing the low speed function of the fan with an external power resistor, as a salvage yard fan may well have the same problem, if that is the problem.

Radiator fan repair, courtesy of Vortex, here and UK-MKIV forum - Handy Topics & Guides - BRISKODA

 

Alright, another question, the right fan (LHD) doesn't start with the AC, is it also suffering from the same problem? 

If the A/C hasn't got any (or not much) refrigerant I'm not sure it would try to switch on the fans at all?  I think it's different to what I'm used to, having a pressure switch rather than a sensor, so I'm not sure. 

If it also doesn't come on until the same high temperature, and it has three wires coming from its motor, then yes, probably.

 

1 hour ago, MarkusDaMan said:

the right fan (LHD) doesn't start with the AC

I'd agree with @Wino about this. I don't know Swedish law, but in the UK you could get the AC regassed for under UK£80. Or an AC fault diagnosed for free by the regasser.

I switched out both fans to new ones, changed the three fuses on top of the battery, changed thermocontact on the radiator. 

 

They wont run at all now, might be the relay being dead? Next is cable broken due to all the fiddling around in the engine compartment. Ideas?

I had no refrigerant for months to the point the compressor was smoking. Now it’s summer regassed and that’s working ok. Phew.

 

re fans, my right hand one is dead, there’s a useful video for testing here 

https://youtu.be/Af-jT9cAioM

 

ie unplug thermo rad connector switch and connect the 12 and 4 o clock (as you look at it) connectors on the plug-  Both fans should run. Low speed.

 

Switch on ignition and connect 2 lower connectors (4 & 8 o’clock) and the high speed should run.

 

in both cases my right fan didn’t rotate, but if I moved it by hand it wanted to go, so the connection was there. I also found the main black alternator ground on the battery top almost melted through.

 

03 Octavia VRS

Be careful with that 'main black alternator ground' because I'm pretty sure that's the 12V connection; got a photo?

Yes I’ve ordered a new fuse box. Not driving much at the mo so time to fix these niggles.

 

 

Yep that's the positive connection. May need a new crimp on the end of that wire, that's probably what caused the overheat.

Yes I will treat with care.

 

Trying to think how long it's been like this. Perhaps a couple of years back, lengthy traffic jam in sweltering weather resulted in engine becoming very odd, multiple warning lights and no power, limped to destination. This odd behaviour has never repeated, but may have been when the fan end-of-lifed and caused that current increase...