Main radiator Fan Manual Override?

Seb_Gurkyh

Seb_Gurkyh

Member
Germany
I'm currently sitting at the foot of a large Hill with only one way over it and the Water temperature at 105 C and the gauge reading about the Same.
Is there Any way to force the cooler Fan to come on manually without putting Further load on the engine or am I stuck waiting until it cools down from being turned Off and parked in Shadow?
Dousing the Radiator with water does some good but there is Not Infinite water.


What even is the max acceptable temperature for an 05 ATL If that Makes Any difference?
 
Presumably if the fan is not running at that temperature, there is a fault with the fan, so manual override may not be an option anyway. Have you checked the fuses?

RAB
 
Waiting about an hour Got it to Cool down to about 82C, turning the AC on on "LO" did Not make the Fan Turn on (engine running) - I am now up half the Hill though it took only half a Mile for it to Go to 92 again... ?
 
Can you not turn your ventilation up to full heat and fan speed and drive with the windows open to act as a bit of a heat sink? Had to do that with an old transit 20 years ago in a heat wave in a traffic jam - had read about the trick as a kid but never tried it in practice until then. It wasn't the most comfortable thing I've ever done but it did help the temperatures.

Or are all the fans immobile?
 
Air con runs full hot (water) all the time and mixes fresh air to regulate the temperature. The fan on climate cars effectively has 3 speeds.
A low speed when the climate is switched on regardless of coolant temperature. A second medium speed when the coolant reaches about 95 and a third fast speed for over temp at about 103. If the fan is not running at all suspect at the least a faulty connection to the fan controller module or a failed controller module or seized or bad connection on the fan motor. As Robin has asked can you physically spin the fan?
 
Seb, this thread may help diagnose the controller / wiring....

Radiator fan not running

Hi, as the temperature starts to rise I have been looking to get my aircon going again, the radiator fan motor cable was knackered last year and after I fixed it and recharged the aircon it worked well. This year the fan does not run at all, with the engine at 90 and the aircon set at low the...
www.a2oc.net

If the fan does not come on the climate shuts down.
 
Thanks for your help, guys. :)

I looked at the fuses, but could not tell which one this should be as the fuse panel is nothing like the sticker in the cover... ?
German A2 Wiki also talks about a hidden 40A fuse above the main panel but I did not have tools with me.
Will try and do some more research on getting to that fuse and/or finding out what the true order is in the "normal" pannel.

Turning on the heat on full blast whenever having to come to a stop seemed to do the trick for the road home at least, Thanks @Robin_Cox I did not think of that?

For the radiator fan, I did another test by coming to a stop on a motorway layby after climbing yet another hill.
Stopped the car, left engine running and aircon on blowing a little cold air. Coolant temp when stopping: 92C
Ran out to take off the bonnet to check fan: Fan not turning while coolant temp steadily rose to 102C at which point I got going again with the aforementioned heat set to HI and me cooking at 30C outside + heat on ?

While trundling along at 60mph on the motorway the aircon worked fine however with coolant temps only going up marginally on longer climbs (max ~94C or so when it would sit at 87C on flat or downhill parts - the original problem of post #1 occured in an uphill 7mph zone which I suppose makes sense if the fan does nothing)

Also, I'd only just done a VCDS scan the day before yesterday with nothing special coming up - is the fan system not monitored?


Is the fan control module the same regardless of engine & model year? If so, I guess I could try and swap it over from my 03 Aircon BBY?
 
There are two fan control variants, one for models with A/C and one without, so you can swap over. Are you sure that a possibly failed fan controller is your only problem? On a 1.2Tdi the cooling fan only comes on rarely, usually on a hot day in heavy traffic.

Incidentally, some time ago I bought a replacement controller but then opened up the old one and replaced the internal Darlington transistors. It worked; the new one is still on the garage shelf.

RAB
 
Seb_Gurkyh said:
I looked at the fuses, but could not tell which one this should be as the fuse panel is nothing like the sticker in the cover... ?
Click to expand...
The fusebox in RHD cars is inverted, and the label on the fusebox cover may or may not reflect that.

This issue is discussed in some detail elsewhere, such as here:

Information - Audi A2 Fuse , relay diagram

Fuse: 1 - Control unit with display in dash panel insert 10A ------------------------------------------------------------- 2 - Voltage Stabiliser 20A Radio Amplifier Aerial Selection Control Unit Operating Electronics Control Unit, Navigation Navigation Interface...
www.a2oc.net

where I give what is hopefully a clear explanation of the actual layout.
 
Update:

My fusebox confusion was due to trying to see in it in a bright environment - couldn't see that each one is actually numbered.
Number 4 is apparently not supposed to be there either way though.

Fuse 31 is fine, cruise control also works as expected.


There is still no error to be found through VCDS.


Checking behaviour on my BBY confirms that the radiator fan should come on as soon as the AC is turned on, even with the car only just having been turned on.

Trying a few things in the ATL engine bay, the fan cannot be started by turning it manually, however I was able to make it start momentarily by tapping the control module, so I suspect that the module is defective. Moving the cables did not produce this behaviour.

Can anyone advise on how to remove the 3 plugs from the control module without breaking them? I've not had a ton of luck getting this type of plug off in the past unfortunately ?

1624120320613.png
 
This youtube video explains the process of releasing the connectors. As simufly says pressing down on the plug before releasing the lock tab is the key


Cheers Spike
 
Simon has provided you with the trick to remove all push and clip type plugs. When off check each connection for correct voltages and for damage including corrosion. If all OK then replace the controller. As you did get the fan to turn electrically then most likely bad or broken connection. My earlier post will help with this.
 
If you can't find anything wrong with the connectors, prise the module open and replace the three (from memory) Darlington transistors inside, if you are handy with a soldering iron. You will otherwise throw it away anyway, so nothing to lose. You will also need some heat sink compound. The part number will be marked on the devices. Find on RS or similar. It will be a lot cheaper than buying a new controller.

RAB
 
Do not blame the fan control module before you checked out fan itself. It has brushes that can get corroded and disconnected or plainly worn out. I had same problem with my 1.4TDI - fan not working, temps climbing. At that time had not any spare money available to buy a new fan, so I fixed existing one. One brush was plain stuck and other had corroded connection. Test is simple - try to hook fan up directly to 12V and see if it works. It should spin pretty fast on full power.

As for climate control settings, last thing you want to do is set climate to Low and AC on, AC is as dependent on airflow for exchanging heat as is antifreeze cooling radiator, they have the same fan you're having problems with. All you do is adding additional heat near the radiator. Turning AC off and putting climate to HI and blower fan to max is way to go, as climate box has another radiator and it's fan is pushing air trought it cooling antifreeze and heating cabin up.
 
On the audi fsi, if you pull out the sensor connection that measures the water temperature at the bottom of the radiator. It will make the fan go to 100% power.
 
spike said:
This youtube video explains the process of releasing the connectors. As simufly says pressing down on the plug before releasing the lock tab is the key


Cheers Spike
Click to expand...

I Just dont See how this could possibly work.

Having Tried to get the yellow Plug Off as shown in the Video, it has now snapped, as expected. There is also No way to push down on the connector as there is no give.

Wondering If the Control Module itself can be taken apart by opening the Tabs at the top so the now broken-in-place connector doesnt have to come Off as I'm guessing that cant be replaced..
 
Seb_Gurkyh said:
Wondering If the Control Module itself can be taken apart by opening the Tabs at the top so the now broken-in-place connector doesnt have to come Off as I'm guessing that cant be replaced..
Click to expand...

See above.

RAB
 
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