Hi Lix, Both Rad fans will run if A/Con is ON. If they run with A/Con OFF then check fuse No 16.
Flickering dash etc is dashpod processor problem & as you say cures once warmed up.
Happened to mine while in warranty, but that was at least 16 years ago. Dash pod replaced by Audi.
Remove dashpod & send away for repair.
For future info, always keep drivers door closed when reconnecting battery as the surge can cause dashpod probs.
Hoggy.

 

Hi Lix, Both Rad fans will run if A/Con is ON. If they run with A/Con OFF then check fuse No 16.
Flickering dash etc is dashpod processor problem & as you say cures once warmed up.
Happened to mine while in warranty, but that was at least 16 years ago. Dash pod replaced by Audi.
Remove dashpod & send away for repair.
For future info, always keep drivers door closed when reconnecting battery as the surge can cause dashpod probs.
Hoggy.

Thanks for the reply. I take it pulling the heater control knob out turns the ac off, it which case the fans still run.
Fuse 16 is ok, if I take it out the fans run but a lot slower and stay on with ignition off.
Thankfully I read a few threads about removing the pod so doors were closed and battery disconnected and left for 15 mins.
Really hoping there a DIY fix, can't afford to send the pod off at the moment. Will do a bit more searching and maybe look at reflowing the pins on the processor.

 

Hi, Fan problem could be the 2 stage thermal switch in rad or the Fan control module, beneath battery.
Coolant temp sensor is for indication only & does not control the fans.
Hoggy.

 

Will do a bit more searching and maybe look at re-flowing the pins on the processor.

Yes, the fix is probably a dry joint somewhere. Unfortunately the skill is knowing which component(s) need the re-flow.

I expect there's a list of common culprits for various problems. For example...

LCD with missing lines: Usually display flatflex cable. Sometimes a re-flow works, but my dash was broken and back to the repairers under warranty in under a month to have the whole glass replaced.

Illumination on fuel and temp gauges: Surface mount resistor directly above LCD. Well within my DIY soldering skill level, but the trick was finding the component! Worth re-flowing all similar large surface mount resistors while you're in there.

Regrettably I don't yet know of any others.

 

Hi, Fan problem could be the 2 stage thermal switch in rad or the Fan control module, beneath battery.
Coolant temp sensor is for indication only & does not control the fans.
Hoggy.

I've ordered a switch so will see how that goes, looking for a guide on how to fit, it looks in an awkward spot for access, battery and tray out.

Off to find a repair manual pdf

 

Will do a bit more searching and maybe look at re-flowing the pins on the processor.

Yes, the fix is probably a dry joint somewhere. Unfortunately the skill is knowing which component(s) need the re-flow.

I expect there's a list of common culprits for various problems. For example...

LCD with missing lines: Usually display flatflex cable. Sometimes a re-flow works, but my dash was broken and back to the repairers under warranty in under a month to have the whole glass replaced.

Illumination on fuel and temp gauges: Surface mount resistor directly above LCD. Well within my DIY soldering skill level, but the trick was finding the component! Worth re-flowing all similar large surface mount resistors while you're in there.

Regrettably I don't yet know of any others.

Thanks, I have sucessfully replaced the pixel screen, so will keep plugging away with the soldering iron until I fix or break it .

 

Hi, Fan problem could be the 2 stage thermal switch in rad or the Fan control module, beneath battery.
Coolant temp sensor is for indication only & does not control the fans.
Hoggy.

Thanks Hoggy, bit more info, I have the switch for rad. Used the 49c to look at temp and this starts at 132° and as mentioned both fans on full. Temp then drops to 60ish, and starts to rise up to 82, couldn't tell what point fans went off as I was driving. May let it warm up from cold and log better what happens. Does this help with diagnosis? Where does the ac menu get coolant temp from?
Thanks Alex

 

Hi, Fan problem could be the 2 stage thermal switch in rad or the Fan control module, beneath battery.
Coolant temp sensor is for indication only & does not control the fans.
Hoggy.

 

Hi Lix, Code 49 gets the coolant temp from the Coolant sensor, but as I said does not control the fans.
Fans are only controlled from 2 stage thermal switch & Fan Control Module.
If the coolant temp sensor is new & OEM, dash pod probs have been known to cause false code 49.
Hoggy.

 

Hi Lix, Code 49 gets the coolant temp from the Coolant sensor, but as I said does not control the fans.
Fans are only controlled from 2 stage thermal switch & Fan Control Module.
If the coolant temp sensor is new & OEM, dash pod probs have been known to cause false code 49.
Hoggy.

Thanks, I hope it didn't seem like I was questioning you earlier advice. I was just wondering if it helped further clarify whether it was the switch or controller.
I'll get on and replace the switch as that was the cheaper of the two when the rain finally stops :roll:
The temp sensor is a green one, but no Idea if its original or cheap part.

 

Hi Lix, Code 49 gets the coolant temp from the Coolant sensor, but as I said does not control the fans.
Fans are only controlled from 2 stage thermal switch & Fan Control Module.
If the coolant temp sensor is new & OEM, dash pod probs have been known to cause false code 49.
Hoggy.

Haven't been able to do the radiator switch yet. Tried from top, but not doing it that way. Underneath is a bit better. Replaced the coolant sensor and code 49 temp still starts at 121°c so guessing it's the dashpod or wiring?

 

Hi Lix, Code 49 gets the coolant temp from the Coolant sensor, but as I said does not control the fans.
Fans are only controlled from 2 stage thermal switch & Fan Control Module.
If the coolant temp sensor is new & OEM, dash pod probs have been known to cause false code 49.
Hoggy.

Haven't been able to do the radiator switch yet. Tried from top, but not doing it that way. Underneath is a bit better. Replaced the coolant sensor and code 49 temp still starts at 121°c so guessing it's the dashpod or wiring?

Hi, I'm afraid so, did you use an OEM coolant sensor? if sensor is disconnected does coolant temp indication still read high?
Hoggy.

 

Hi Lix, Code 49 gets the coolant temp from the Coolant sensor, but as I said does not control the fans.
Fans are only controlled from 2 stage thermal switch & Fan Control Module.
If the coolant temp sensor is new & OEM, dash pod probs have been known to cause false code 49.
Hoggy.

Haven't been able to do the radiator switch yet. Tried from top, but not doing it that way. Underneath is a bit better. Replaced the coolant sensor and code 49 temp still starts at 121°c so guessing it's the dashpod or wiring?

Hi, I'm afraid so, did you use an OEM coolant sensor? if sensor is disconnected does coolant temp indication still read high?
Hoggy.

Hi, Found out recently that an extremely high temp reading from sensor ( it has 2 outputs one to gauge & one to ECU) can cause the fans to run, even though it's a false reading. Curing the false high temp reading may cure the fan problem.
Hoggy.

 

Hi, I'm afraid so, did you use an OEM coolant sensor? if sensor is disconnected does coolant temp indication still read high?
Hoggy.

Hi, Found out recently that an extremely high temp reading from sensor ( it has 2 outputs one to gauge & one to ECU) can cause the fans to run, even though it's a false reading. Curing the false high temp reading may cure the fan problem.
Hoggy.

Thanks for reply, that's very interesting. I used a febi bilsien one, so not the very cheapest. Can't afford to throw any money at it .
I didn't check temp with it disconnected. Easy one to try.
I'll do some searching on high temp when cold. Or post a new question.