Don't worry about the AC. I guess it has low or no refrigerant, which will mean that the HVAC control unit doesn't try to operate the compressor. This in turn will mean that the fan never gets triggered by rising refrigerant pressure.  If it is working, it provides a quick and easy way to test fan function, but it doesn't so don't bother with it.

 

I think your fan probably works OK now, but there might be a subtle fault like one or two of the carbon brushes (there are four in opposing pairs) being stuck in their slots. This can make the fan intermittent in starting up.  

I may have a spare fan (from a more recent car) that will suit your car, I'll research this later for you.

Bit busy with work now though. 

 

 

 

37 minutes ago, Pete_Ex-Wino said:

Don't worry about the AC. I guess it has low or no refrigerant, which will mean that the HVAC control unit doesn't try to operate the compressor. This in turn will mean that the fan never gets triggered by rising refrigerant pressure.  If it is working, it provides a quick and easy way to test fan function, but it doesn't so don't bother with it.

 

I think your fan probably works OK now, but there might be a subtle fault like one or two of the carbon brushes (there are four in opposing pairs) being stuck in their slots. This can make the fan intermittent in starting up.  

I may have a spare fan (from a more recent car) that will suit your car, I'll research this later for you.

Bit busy with work now though. 

 

 

 

 

 

Dear Pete, Much appreciated for your time please,

Thought to share with that  when car running idle for quite a while yesterday, FAN was never kicked off  even with temperature reaching higher at one time CAR had abrupt shutdown as opened coolant it was very hot I guess as warm air was flowing out, Afraid to ask you  do u mean Control unit is healthy or broken and need change. So u reckon could be FAN issue not FAN CONTROL unit assembly.    

Whenever free or possible please advice , hope this message does not disturb you on work.

 

Many thanks 

Kind Regards 

raky

 

 

Control unit is probably healthy, fan may also be.

 

The other obvious possibility is that the coolant is not getting circulated to/through the radiator correctly.  This could be happening because of a stuck-closed engine thermostat, or possibly a failed water-pump.  If the coolant isn't getting to the radiator thermoswitch, the fan will not get triggered even if everything electrical is OK.

 

To check water pump is working, with cold engine start the car with the coolant expansion tank lid off.  Observe where the small hose at the top of the tank enters, and see if a trickle of water is coming from it. Get an assistant to rev the engine a bit, and see if that trickle gets stronger.

 

To check thermostat, feel both radiator hoses near the radiator (carefully, avoiding burning yourself on anything nearby) when the engine is fully warmed up, both should be hot, indicating that coolant is going through. If one remains cool, thermostat may be your problem.  

 

 

4 hours ago, Pete_Ex-Wino said:

Control unit is probably healthy, fan may also be.

 

The other obvious possibility is that the coolant is not getting circulated to/through the radiator correctly.  This could be happening because of a stuck-closed engine thermostat, or possibly a failed water-pump.  If the coolant isn't getting to the radiator thermoswitch, the fan will not get triggered even if everything electrical is OK.

 

To check water pump is working, with cold engine start the car with the coolant expansion tank lid off.  Observe where the small hose at the top of the tank enters, and see if a trickle of water is coming from it. Get an assistant to rev the engine a bit, and see if that trickle gets stronger.

 

To check thermostat, feel both radiator hoses near the radiator (carefully, avoiding burning yourself on anything nearby) when the engine is fully warmed up, both should be hot, indicating that coolant is going through. If one remains cool, thermostat may be your problem.  

 

 

Dear Pete , Quite excited for doing  diagnostics, seems it is full time job , really apprecaite your patience and support . This morning new issue possible we may have messed up some wires as we fiddling with 3 different fan control module we did not fit all tested 1 by 1 kept temporary hanging ,  removed and fixed control module unit  , this morning engine light starting blinking abs light is on with few more light,  got scanned from and noted all code, car drives fine driven around 10 miles no issue smooth , I have fitted my original fan module controller now removed ebay old one ,  I reckon since most fuses are top of battery plastic holder connecting/disconnecting battery may have broken some fuses checking one by one again, defiantly I remembered last time when ABS light came in i found the  4th or 5th number fuse was broken.

 

I have checked pipe going to radiator is defiantly gets warmer or vent hotter , but not radiator itself it was full cold surprisingly I have touched the coolant switch which was also very cold but pipe connect the radiator was pretty warm , coolant is continuously  flowing in coolant tank  little bit weak stream( will get back on stronger stream very soon after rev, will do very soon ) all pipes were hot read ur many advices on this website and was thinking about thermostate and tested all 

 

My assessment - 1. Coolant is circulating for sure , 2. Radio pipe and engine pipe are get hotter based on car I keep running 3. coolant is flowing in coolant tank 4. Radiator is NOT getting HOT at all 5. Radiator switch is by touching also doe snot seems hot.    

Not sure how coolant is circulating if it is not going inside radiator. 

 

Error code which is giving clarity : 

1. 18049 Check DTC error code  for AC

2. 17604 – Lambada sensor - ( known to me disconnected time bingo waiting for new sensor)

3. 17586- Lambada sensor ( known to me disconnected time bingo waiting for new sensor)

4. 17524 - Lambada sensor – known to me disonected , waiting for new one 

5. 65535 - ( I think connecting /disconnecting battery may have messed ECU which may or may not be serious , but got ABS error , engine light flashing , just happened today never had issue driven 20 miles all looks good)

6. 01596 - AC flap issue I think 

7. 00819 -  ( 2 times – same error don't know why ) High Pressure Sensor (G65): Open or Short to Ground 

8. 00705- Relay for Coolant Fan; Stage 1 (J279) 

9. 00706- Relay for Coolant Fan; Stage 2 (J513)

 

Any thoughts please.

Kind Regards 

raky

 

 

 

Edited 12 May, 20224 yr by raky

ABS light probably from messing with its strip fuse, most other codes probably from disconnecting and reconnecting things. Clear all and see what, if anything returns. 

A/C codes probably recirculation flap problem (standard on most Fabias of this age, largely irrelevant unless stuck shut), and low refrigerant causing G65 one.

Edited 12 May, 20224 yr by Pete_Ex-Wino
Rogue apostrophe autoincorrected

28 minutes ago, Pete_Ex-Wino said:

ABS light probably from messing with its strip fuse, most other codes probably from disconnecting and reconnecting things. Clear all and see what, if anything returns. 

A/C codes probably recirculation flap problem (standard on most Fabias of this age, largely irrelevant unless stuck shut), and low refrigerant causing G65 one.

 

Thanks Pete , Mechanic did clear all code it came back , I shall check all strip fuses again I had tested  5 normal car fuses with multimeter which were next to strip fuses in closed box (  right side 5 wires box)  all looked OK , I think working electronics of car I  should disconnect both terminals of battery not just one .  

 

Sorry I am confused why my radiator is not getting warm at all even though coolant  hose pipe become pretty warm/hot after engine is warmed up . Any pointers please ...?

 

Thank you so much for your support and help.

 

Kind Regards 

raky

 

 

 

Edited 12 May, 20224 yr by raky

Both radiator hoses get hot? You said hose, not hoses?

22 minutes ago, Pete_Ex-Wino said:

Both radiator hoses get hot? You said hose, not hoses?

Sure Pete , I understood , I will check both hoses , I believe 1 is up  entering top of  radiator very big hose  ,  which I have checked many times were always hot  when car was idle running and 2nd hose  is down end  of radiator, I shall drive car 1-2  miles and check and update you please  same time I shall also check with high rev  if coolant speed in tank  also increases or not ?

 

Thanks  

A little further than 1-2 miles, maybe 3-4 to be sure that the thermostat should have opened. 

Thanks Pete drove good 5 miles in city conditions though it is raining here so temp is bit low both hose are almost same warm touchable , I would say lower hose may be 10to 20% less warmer but one thing I have noticed that lower part of radiator is very cold I can sense coldness in it and only upper part is warm temp does not look like same as pipe as expected but cooler than pipe but warm.  May be radiator is not working as expected possibly radiator switch area may be just cold. Any thoughts please I am typing u from car 5 miles away from home. Regards

It sounds like not enough coolant is circulating through the radiator. I would change the engine thermostat rather than the radiator, as this is cheaper and much easier.

Edited 12 May, 20224 yr by Pete_Ex-Wino

Dear Pete So do u think radiator may be blocked and if I use radiator cleaner and flush it few times would it make it better which  may clean the  gunk  please?? I have driven back 5 miles would validate abt temp  from my friend on both hoses again and update here . Much appreciated 

No, as I said, it's more likely to be a problem with the engine thermostat.

 

Flushes never really work on things that are blocked, because there's no flow to take the flushing agent there if it's blocked!

 

Try the thermostat.

Dear Pete, Another update changed  number 4 fragile fuse  , ABS sensor light gone , just engine light on , I think all fuses must eb chnaged at least 2-3 years once they just cost few pennies,   I will get  thermostat change  and update the behaviour, my courier had also reached  dartford hope to get all parts by Monday.

 

I am driving 4-5 miles with full cold air and engine bonnet open and car is running smooth does not it is heating , hope it is fine please.

 

 

Much apprecaited your support and time. 

 

Stay blessed .

 

Kind Regards 

raky 

Dear Skoda Owners, 

Please find below steps for broken Fan related issues  in skoda fabia mk1 which I have  gained knowledge  from respected & humble  Skoda expert  @Pete_Ex-Wino 

The possible issues could be in  any one or more than one area -   1. Radiator , 2. Fan  3 Thermostat switch, 4 Fan control unit , 5 Wiring 5 ECT ( engine temperature sensor) 6. Coolant Tank 7 Coolant   , 8 coolant pipes/hoses  9 Strip/Normal fuses.

 

1. Always start with basics - Remove each fuse related  to radiator fan and physically check  each of them,  if they are fragile please just change it , would not cost you more than few pennies for sure but if u  ignore defiantly cost u huge pain. ( found two stirp fuse of my car were broken even though they looked healthy visibly & always assumed that they are fine) 

2. Check if Fan is healthy ,  remove fan switch short 1-2 and 1-3 pins for low and high speed u may refer beginning of this thread you will find the image.( my case 2 broken  fuse  caused issue)

3. If fan is healthy check both hose pipes /inlet an outlet from radiator if they are getting warmer or hotter

4 Check if radiator is warmer. (My car radiator is not getting warmer symetrically more investigation needed)

5 Check if there is flow of coolant in coolant tank

6 Check coolant tank is not leaking ( mine was leaking when it was getting warmer

 

In conclusion I think my radiator is not getting warmer enough to kick the fan module to start the FAN, as of now undertaking is thermostat may be broken or radiator can also be bad.

 

 

Keep u posted the progress of it , I still feel Skoda is strong car with minor sensor related issue which of course have life but we owners must understand all sensors which may be round 15-20 .. 

 

I am afraid 4 Out of 5 mechanics could have solved this issue in minutes but there is greed every where on this planet , millions lost life due to covid and humans did not learn greed never ends.

 

Happy driving .

cheers,

ray

Hello Experts ,

Does these test to check health of thermostat  holds good please. Anyway  I am planning to change my car thermostat bought it already not expensive part, may take little time for mechanic to change but otherwise fine. Have seen below info  on net for thermostat issue , please advice if they make sense , as it may help all  to pin point issues, please feel free to modify should u feel info is incorrect.

 

Thermostat Tests:  

Test 1. Cold engine test: Open the hood and remove the radiator cap/coolant tank lid. Start the engine. Observe coolant action by looking down into the radiator. The fluid should not be moving.
Verify : When an engine is cold, the thermostat should be closed, thus bypassing the radiator.   ( In my case it coolant Strats flowing immediately after cold Strats , suspecting thermostat struck at open position)

Test 2: Cold engine test: Start the engine. Turn on the heater. Time how long it takes the engine to warm up enough for the heater to actually produce heat in the passenger compartment.
If it takes more than five minutes for the heater to produce heat, it is a sign that the thermostat is stuck open, allowing the coolant to detour through the radiator all the time. This causes it to take a good deal longer for the engine to warm up.   ( Will test this, never done  )
Test 3 : Warm (not hot!) engine test : Open the hood and remove the radiator cap. Start engine. Look down into the radiator and observe coolant action. The fluid should be swirling vigorously.
When an engine is warm, the thermostat is in the open position. This allows the coolant to flow through the radiator causing vigorous movement.
 

 

Thanks 

Kind Regrds

raky

Hi Experts , Just sharing as it may help somebody similar situation even though I have already planned, request Mechanic  to  change thermostat switch and fan control module,

 

I have noticed that

- on cold Start the coolant starts flowing immediately in coolant tank. ( not sure ideally it should happen or not ) as I rev coolant flow increase .

- Car reaches 90 degree on dashboard after at least driving 2 miles. ( not sure it should take so much time ) or after 8-9 minutes running idle.

- The car interior  gets warmer after 2 minute of switching on moved on highest temperature &   after 5 minutes it become  little bit warm but not like earlier it used to get very hot.

 

 

Cheers 

raky

 

 

 

 

   

Dear Experts , 

I have gone through many thread having radiator fan  issue and trying to understand the root cause of issue , below are my  understanding, please correct me  if I am missing something. 

 

1. Thermostat may be working fine - Tested car started & ran idle for good 5 -15 minutes with full AC on - observing the radiator return hose pipe to engine & initially  it was dead cold but Inlet pipe was bit warm so thermostat was closed after few minutes return pipe became warm rather hot & radiator was light warm, which made  me think that thermostat is working as expected.  (please correct me ) 

2. Thought radiator was blocked but seems  while driving with low temperature radiator gets cooler fast as though nothing has passed from it, but in stationary car, while running idle, it was symmetrically warm so confirmed me that coolant is passing through radiator.

3. Changed Radiator thermo switch last week, so it cannot be faulty 

4. Shorted 1 & 2 , 1&3 pins of Thermo switch connector and fan ran with slow/high speed mode which proved that FAN is fine (of course 2 strip fuses were blown). My understanding is Fan Control module (FCM) is also working fine since when the shorting of thermo switch was done  it  messaged FCM ( simulating high temp behvaiour) and FCM  signalled back to fan to come in action. ( Please correct if I am missing something)   

5 . Since I am not driving car but today observed that car may be getting overheating as noticed that after few minutes of idling  car was abnromally shut down. Temperature gauge was struck on  90, but my diagnostic app initially was showing 70 degree of coolant temperature but later when car abruptly got off app was showing around 81 degree. It means temperature may have crossed 94 degree & ecu sensed the danger and switched off the car as preventive measure. Sorry I don't quite understand the  flow of messages & corresponding actions, how ECU gets temperature info from ECT (Engine coolant temperature sensor), or thermoswitch & senses  the danger and instructs FCM to signal for FAN action. I think ECU may be getting info about temperature from 2 sources thermoswitch & and ECT and then acting on it.

So in my case above test number 4  shows that FAN to FCM signalling to and fro is working fine, but ECU to FCM connectivity may have some issue again I don't know about and all are assumptions.

 

6. Since car is behaving as expected on temperature  wise so assuming ECT is working fine 

7 . Only issue could be faulty ECU or ECU to FCM connectivity.

8 Sorry, I don't know if FAN have any electronics component which needs some X  volts to trigger it and those component may be faulty. As not sure step 4 may have already proved it about FAN health.

 

Hope for expert opinion and advice of this matter at least I can feed our analysis to car electrical expert so that it will make his life easy .

 

Much aapreciated for reading long message please.

Thanks, 

Kind Regards

raky 

 

 

 

 

 

Do you have any record of either engine thermostat or engine coolant temperature (ECT) sensor ever having been replaced since the car was built 15 years ago?

Change both if not.

 

On the basis of your diagnostic app temperatures, the engine is not getting hot enough for any problem, nor any fan function, but the app might be getting bad info from the engine ECU (which directly reads ECT sensor) if that  ECT sensor is reading wrongly. 

 

The radiator thermoswitch actually has two independent switches inside, with different temperature thresholds, for activating each speed of fan operation by causing the relay coils in the FCM to be grounded and so energised. These thresholds are approx 95 and 102C.

No ECU nor other 'intelligent electronics' is connected to the thermoswitch in any way, hot coolant is the only thing that can make it switch. By loom testing you have proved that if those thresholds are reached and the switches activate, the relays inside the FCM will turn on to power to the fan. There are no electronics within the fan. 

Until the thermoswitch area of the radiator is reaching these high temperatures, no fan operation should be expected. 

 

 

If the engine shuts down unexpectedly after a few minutes of idling, there must be some other problem completely separate from any of this stuff, I think.

 

 

 

 

 

 

 

13 hours ago, raky said:

3. Changed Radiator thermo switch last week, so it cannot be faulty 

A new part could be wrong or faulty for many reasons, never assume just because a part is new that it is the correct part or fully functioning even if it works.  As you have found before it's important to fit the correct good quality parts.  Note I am not saying your rad switch is faulty just not to assume it can't be.

 

5 hours ago, Pete_Ex-Wino said:

Do you have any record of either engine thermostat or engine coolant temperature (ECT) sensor ever having been replaced since the car was built 15 years ago?

Change both if not.

 

On the basis of your diagnostic app temperatures, the engine is not getting hot enough for any problem, nor any fan function, but the app might be getting bad info from the engine ECU (which directly reads ECT sensor) if that  ECT sensor is reading wrongly. 

 

The radiator thermoswitch actually has two independent switches inside, with different temperature thresholds, for activating each speed of fan operation by causing the relay coils in the FCM to be grounded and so energised. These thresholds are approx 95 and 102C.

No ECU nor other 'intelligent electronics' is connected to the thermoswitch in any way, hot coolant is the only thing that can make it switch. By loom testing you have proved that if those thresholds are reached and the switches activate, the relays inside the FCM will turn on to power to the fan. There are no electronics within the fan. 

Until the thermoswitch area of the radiator is reaching these high temperatures, no fan operation should be expected. 

 

 

If the engine shuts down unexpectedly after a few minutes of idling, there must be some other problem completely separate from any of this stuff, I think.

 

 

 

 

 

 

 

 

Dear Pete, hope I have not spoiled ur weekend, Thank you so much for sparing time on weekend so kind of you. 

 

 

Yes I remembered thermostat or ECT was changed but since I have opened ECT recently and found that it was original vw so cannot be that  I am certain now that it was thermostate was changed when my car temperature gauge was not working must be around 6 years back.  As I drive 30 miles so before going to mechanic I had bought bought thermostat & ECT and later returned back ECT because it did not have O-ring , and returned thermostat and re bought again euro parts. I have even requested my humble mechanic for changing all parts he Kindly refused as wanted to save my bucks . Thanks for advice  will do as advised change both these parts live in very hot temperature should be strong and of good quality. I have only local option srsparts or Europarts. 

 

"By loom testing you have proved that if those thresholds are reached and the switches activate, the relays inside the FCM will turn on to power to the fan. There are no electronics within the fan."

Thanks for confirming please, relived now. 

 

 

"If the engine shuts down unexpectedly after a few minutes of idling, there must be some other problem completely separate from any of this stuff, I think."

 

Please excuse me on my ignorance , this behaviour have been noted few times , as o2 sensor has been disconnected currently running on default values so possibly could be something to do with that ,  hope my  ECU is not faulty which is unable to send the signal for fan or causes abnormal shutdown. 

 

I understand shortening 1,2 & 1,3 pins of radiant switch would have tested smaller switch of FCM functionality and FAN health but  do u think I need to test  4 pin bigger switch of FCM for I/O voltage after warming car to make sure all going ok, assuming it gets instruction from ECU for fan when temperature crosses threshold.   Please find some document found which may be for different car but may be close to my car FCM.  

 

Please correct me if my understanding is incorrect , is there any voltage check can help me if  after changing ECT and thermostat switch the issue is not resolved.

 

NOTE: Added 

Please also advice CAN I drive car locally after opening  keep down window glass, leaving  bonnet open and running cold air fan.  

MY CAR never crossed 90 degree on dashboard even though I drove 30 miles , but stopped for 20mi after every  10 miles and weather was not bad ( 10 degree). 

 

 

Thanks

Kind regards  

 

 

 

 

 

 

 

 

Cooling Fan Control .pdf

Edited 15 May, 20224 yr by raky
Added picture of FCM/note

ETA: dash temperature gauge is set to show 90 even though the real temperature might be within a range around 90, this is to save drivers worrying about the exact temperature and possible normal fluctuations.

 

I can't help you any more I'm sorry to say Raky. I don't have enough time.

10 minutes ago, Pete_Ex-Wino said:

I can't help you any more I'm sorry to say Raky. I don't have enough time.

Dear Pete , Much appreciated, you had already spend lot of time & taught great diagnostic  approach & helped me ,Thanks you so much for all,  I can imagine that u have also limit and even same here, cannot do any more beyond my control, I had already given up spoken to few electricals experts for next week appointments , I think after changing advised part, car will go to  electricians & hopefully they would be able to look further.

You have given me many good pointers and  Thank you so much for that as well.

I shall update complete info so that it can help others generally people don't update solution once their car issues are resolved. 

 

Stay blessed and please keep sharing ur knowledge and helping Skoda owners  and also saving planet.   U deserved a  champagne bottle and thank you card.

 

Thanks 

Kind Regards 

raky