FORD FOCUS Aircon/fan problem
#1
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FORD FOCUS Aircon/fan problem
MY 02 ford focus has a really strange problem, here are the symptoms
The 2 radiator fans are coming on very frequently, a lot more than normal.
The Heater/blower fan only works on No. 4 setting (ie no fan on pos 1,2 or 3)
The aircon compressor kicks in and the button light comes on but still no heater/blower until position 4, and then the aircon light goes out.
Can anyone shed any light on the problem, or suggest what to look for, i have checked as many fuses as i can and theyre ok,
I do know from the manual that the 2nd rad fan has somthing to do with the aircon!!!!
ANY HELP WOULD BE MOST APPRECIATED
The 2 radiator fans are coming on very frequently, a lot more than normal.
The Heater/blower fan only works on No. 4 setting (ie no fan on pos 1,2 or 3)
The aircon compressor kicks in and the button light comes on but still no heater/blower until position 4, and then the aircon light goes out.
Can anyone shed any light on the problem, or suggest what to look for, i have checked as many fuses as i can and theyre ok,
I do know from the manual that the 2nd rad fan has somthing to do with the aircon!!!!
ANY HELP WOULD BE MOST APPRECIATED
#3
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Re: heater
Originally Posted by zvhturbo29rs
check resistor behind the glove box, take glove box out should be green in colour.have seen these burnt ot before. should replace the wiring loom and resistor.not expensive.hope this helps.
What he says also if your heater control is set on windscreen the air con is active even if its not turned on !.
Regards Doug .
#5
As said resistors often burn out, there is a modified loom to stop this, well at least on mondys there is.
If it is hot the fans do run a lot, both are used when engine cooling is needed if it is hot enough, only one normally runs with air con on.
I don't think it will be the case from what you describe but both coming on also happens when it senses MAJOR ENGINE malfunction, so a dicky sensor can cause this, and unbelievably so can the PATS module, as mine got waterlogged and did this very thing, cleaned it out dry it off all ok!!
tabetha
If it is hot the fans do run a lot, both are used when engine cooling is needed if it is hot enough, only one normally runs with air con on.
I don't think it will be the case from what you describe but both coming on also happens when it senses MAJOR ENGINE malfunction, so a dicky sensor can cause this, and unbelievably so can the PATS module, as mine got waterlogged and did this very thing, cleaned it out dry it off all ok!!
tabetha
#6
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funnily enough the passenger side has had a good soaking, since the bloke who service it didnt seal the pollen filter properly. where is the PATS module by the way
#7
I am not even sure your car has one!, does it have a red tag in the key ?
All I know is the pats module was under the dash bit on the mondy right up front under the ash tray area.
It might pay to phone FOCUS & MONDEO PART, 01603 866999, as they will know where it is.
Is your car starting ok and all that, is the pats light behaving ?
tabetha
All I know is the pats module was under the dash bit on the mondy right up front under the ash tray area.
It might pay to phone FOCUS & MONDEO PART, 01603 866999, as they will know where it is.
Is your car starting ok and all that, is the pats light behaving ?
tabetha
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#10
I have a similar problem of no heater blower in my Ford Focus, in my case nothing works and when i change the fuse in the engine compartment for the heater fan it just blows , i too had the problem of water getting in through the filter , could the solution bee the same a blown resistor if so are they easy to get to and get out , there are quite a few breakers yards near me so was going to have a go and replace
Regards Dave
Regards Dave
#12
Was your resister pack burnt out because i have the same problem with the heater and air con not working on 1 2 and 3. i have checked the heater switch which is ok. i have checked all fuses and relays which are ok the only thing i can find is the resistor which appears a little rusty but not burnt out. I am some what confused now and dont want to go to ford and buy all diffrent parts to fault find.
Was the resistor pack blown or not?
Thanks Wipper
Was the resistor pack blown or not?
Thanks Wipper
#13
PassionFord Regular
I have a similar problem of no heater blower in my Ford Focus, in my case nothing works and when i change the fuse in the engine compartment for the heater fan it just blows , i too had the problem of water getting in through the filter , could the solution bee the same a blown resistor if so are they easy to get to and get out , there are quite a few breakers yards near me so was going to have a go and replace
Regards Dave
Regards Dave
Disconnect the motor and unscrew the retaining screws fron inside the footwell, drop it out and check if it is stiff or turns at all.
Martin
#14
I replaced the resistor in my 1999 Focus today and it still only works on 4 (sometimes it doesn't work at all). The new resistor was from Ford and the old one looked fine.
Has anyone got an idea of what could be wrong?
Has anyone got an idea of what could be wrong?
#15
PassionFord Regular
Did you check the condition of the connector for the resistor pack. Very common on Mondeo and early Focus to burn that out. About the only bit of a harness Ford sell separately as a repair kit.
#16
Thanks for the advice - I didn't check at the time. I'll have to wait until next weekend to pull it all apart again.
Can you tell me what I should be looking for on the connector, rust, etc?
Can you tell me what I should be looking for on the connector, rust, etc?
#17
PassionFord Regular
Just look for BURNING
Its a high current flow, so if the contacts aren't a tight fit, either the small contact area overheats, or arcing/sparking burns the contacts and the plastic.
The repair kit consists of a new plug and a handful of crimp connectors. Cut off the old plug and crimp the wires on the new one to the harness.
Martin
Its a high current flow, so if the contacts aren't a tight fit, either the small contact area overheats, or arcing/sparking burns the contacts and the plastic.
The repair kit consists of a new plug and a handful of crimp connectors. Cut off the old plug and crimp the wires on the new one to the harness.
Martin
#18
THE COMPLETE SOLUTION - I had a similar problem on my 2002 Focus Ghia Estate, with only no. 4 position on heater blower working. The heater fan sometimes has had a squeaking noise like a leaf was caught in it or something, but not all the time. I took the advice here and replaced the resistor pack behind the glovebox. My local Ford dealer suggested buying the replacement plug in case it was burned out, which I did. Needless to say, the plug was fine on mine. After replacing the resistor, all 4 fan positions and the A/C worked fine. I returned the plug for a refund. After a couple of days the squeaky fan was noticeable again and then I found that only fan 4 position was working. Running the fan on max I noticed a fluctuation in fan speed coincidental with the squeaking. I sussed that the fan motor bearings were the problem and that the electrical overload had blown the resistor pack. This is most likely the cause in all cases, as on the resistor pack, below the green part which encases the resistors there is what appears to be a small resistor soldered between 2 terminals. This is in fact a sensitive, non-resetting thermal fuse. It is rated at 215 deg. C and this is what causes the pack to fail. I removed the fan and motor and found that the motor was stiff to turn. It is set in moulded rubber within the outer housing. By using a flat blade screwdriver to press down the rubber moulding tags the motor and moulding can be removed from the casing. The bottom bearing showed signs of rust but was not worn so I used some engine oil to lubricate it, making sure that it entered the bearing and wiping off all excess (do not allow oil into the motor or brushes!!) I used a long spout oil can to reach the bearing behind the fan too. After turning it rotated freely. The motor and moulded rubber were reinserted into the casing (use a little washing up liquid on the tags, and ensure they fully engage using a flat screwdriver). The fan assembly was plugged in while somebody held it tight as I ran it on the 4 setting. It rotated freely. Don’t just leave it on the floor of the car as it will jerk around when switched on!!! The fan assembly was replaced. Now for the resistor pack. I obtained a replacement thermal fuse from Maplin (228 deg C or 192 deg C as they do not do a 215C) for Ł0.79. I cut off the existing fuse which seems to be welded in place, not soldered, and using a soldering iron, tinned the terminals (and remaining fuse ends). The thermal fuse is sensitive to heat, so I used a pair of pointed pliers to hold close to the fuse to drain the heat as I soldered one end in place, then the other. I don’t know if the fuse is directional but I kept the cone shaped end on the same side as the original. After trimming off the excess wire from the ends of the fuse, the heater resistor pack was plugged in and worked perfectly. No need to spend Ł12 plus from Mr Ford on a new resistor pack when Ł0.79 will do !! My heater blower now works perfectly. I guess the bearing problem may return eventually, signalling the need to replace the fan/motor unit, but they are available on Ebay from Ł25 upwards (may have similar dodgy bearings), so possibly better from a scrap yard if you can examine it first. Otherwise new is Ł170 plus from main dealer.
#19
PassionFord Regular
Phew, have you fixed the root cause though? The stiff blower motor is a result of water coming through the pollen filter, it also causes a wet passenger footwell.
Although the panel has been modified by Ford, the most common cause it that people don't use the fasteners properly and don't replace the double sided foam seal every time the cover is taken off.
Martin
Although the panel has been modified by Ford, the most common cause it that people don't use the fasteners properly and don't replace the double sided foam seal every time the cover is taken off.
Martin
#20
Thanks for all the advice. It has completely died now (position four doesn't work) and even the air recirculation switch is dead. I took the heater resistor out and none of the connections are burnt at all.
I was lead to believe it could be the switch itself which is causing it to completely die in addition to the problem described by philvbarnes. I seem to remember it was very stiff, almost stuck on position 4 when it completely died and I had to force it out of position four. Although it has completely died before and come back to life.
So I pulled the radio out, removed the front panel and removed the switch. It has six connectors on it. I got the multimeter out, set it to measure resistance and with the switch set in the zero position I joined connector one with two, then one with three, etc then repeated the process for each connector. None of them were joined. I then repeated this with the switch in position four and got the same results.
Was this a valid test? Should I expect that when the switch is in position four there should be some connection between the connectors?
I was lead to believe it could be the switch itself which is causing it to completely die in addition to the problem described by philvbarnes. I seem to remember it was very stiff, almost stuck on position 4 when it completely died and I had to force it out of position four. Although it has completely died before and come back to life.
So I pulled the radio out, removed the front panel and removed the switch. It has six connectors on it. I got the multimeter out, set it to measure resistance and with the switch set in the zero position I joined connector one with two, then one with three, etc then repeated the process for each connector. None of them were joined. I then repeated this with the switch in position four and got the same results.
Was this a valid test? Should I expect that when the switch is in position four there should be some connection between the connectors?
#21
PassionFord Regular
Only 5 of the contacts in the connector are used.
#2 is the common.
#1 - Switch position 1
#3 - Switch position 2
#5 - Switch position 3
#6 - Switch position 4
Martin
#2 is the common.
#1 - Switch position 1
#3 - Switch position 2
#5 - Switch position 3
#6 - Switch position 4
Martin
#22
Thanks to everyone for all the help. I'm pleased to report that the heater is fully working again.
I ordered a new switch from Ford which cost Ł21 (for a tiny switch!). I fitted it and the heater worked again. It only worked on setting four until I realised the resistor wasn't plugged in It now works on all settings with the original resistor. Not bad work in the dark at -3C.
So it was the switch all along! I would recommend people inspect the resistor before buying a new one.
The resistor is a nightmare to get at! I had to make this monstrosity to get at it:
The red tape on the bendy joint is to provide some rigidity!
I ordered a new switch from Ford which cost Ł21 (for a tiny switch!). I fitted it and the heater worked again. It only worked on setting four until I realised the resistor wasn't plugged in It now works on all settings with the original resistor. Not bad work in the dark at -3C.
So it was the switch all along! I would recommend people inspect the resistor before buying a new one.
The resistor is a nightmare to get at! I had to make this monstrosity to get at it:
The red tape on the bendy joint is to provide some rigidity!
#23
part number
please could someone who has ordered this part before give me a ford part number for the thing in the "blue box" on this thread and its wireing loom if its required, i have the same problem as is mentioned here, however i have tested all other avenues and the ford dealership is not being helpful and will not try to locate the part number from description they want to see it for themselves and charge me for it too.
#25
OK, there are lots of solutions on here: switches, resistor packs, fan motor assembly. My 1999 Focus has recently (this week) only started to operate on position 4. I have also noticed the damp in passenger footwell. (pdfbt40 you indicate this is due to pollen filter) What is best first course of action?
Ta.
Ta.
#26
PassionFord Regular
There are lots of solutions because because actual faults cascade problems.
1) Fix water leak through pollen filter by sealing the cover/windscreen using correct adhesive strip and replacing clips properly.
2) Check and repair/replace blower motor. The bearing become stiff due to water getting to them.
3) Check/replace resistor pack, or just the thermal fuse. If the blower became stiff it doesn't produce enough airflow to cool the pack and the thermal fuse protects it.
4) If 2 & 3 were OK, check the switch. Usually this is only a problem if there is no blower at all.
Martin
1) Fix water leak through pollen filter by sealing the cover/windscreen using correct adhesive strip and replacing clips properly.
2) Check and repair/replace blower motor. The bearing become stiff due to water getting to them.
3) Check/replace resistor pack, or just the thermal fuse. If the blower became stiff it doesn't produce enough airflow to cool the pack and the thermal fuse protects it.
4) If 2 & 3 were OK, check the switch. Usually this is only a problem if there is no blower at all.
Martin
#28
Sorry to thread jump, but at start of thread it mentioned the fans in front of radiator were on more than usual. Mine has started this where the fans are on all the time. Someone mention the radiator fan switch and another part but cant rememba .
Anyone got any ideas? its on a mk1 1.8 focus?
Thanks
Anyone got any ideas? its on a mk1 1.8 focus?
Thanks
#29
PassionFord Regular
There is no radiator fan switch on a Focus. The fans are turned on and off, slow speed (via (i)another(/i) resistor pack in the shroud) or high speed by 2 relays in the engine bay fuse box. These are operated directly by the PCM/ECU.
I don't know the precise logic involved, but usually assume that the primary measurement that triggers them is the Cylinder Head Temperature (CHT) sensor. Again, except in the ST170, there is no coolant temperature sensor.
The PCM, as well as being part of the aircon clutch switching, takes a signal of aircon on (demand). As the condenser in front of the radiator must have airflow through it for the cooling to work, the PCM switches the fans on.
So suspicion must fall initially on the CHT. That is however strange as its the sensor that is also used by the PCM/ECU to generate the signal for the 'gauge' in the dash. However, my opinion is that the 'gauge' is more of a 3 zone indicator, cool - OK - too hot, not a true temperature gauge as in earlier direct driven vehicles. So the CHT could be sending an 'OK but hot' signal, which would turn fans on, but not show on the dash.
Could be investigated further using an EOBD reader and programme to monitor PCM coolant temperature, or simply replace the CHT.....
Oh, finally, some Focus have a Ford work-around for high under bonnet temperature of an 'old fashion' fan switch cable tied to the battery tray. Its directly wired to the battery so if the temperature goes over ~90, even after the engine is off, the fans come on!!
Martin
I don't know the precise logic involved, but usually assume that the primary measurement that triggers them is the Cylinder Head Temperature (CHT) sensor. Again, except in the ST170, there is no coolant temperature sensor.
The PCM, as well as being part of the aircon clutch switching, takes a signal of aircon on (demand). As the condenser in front of the radiator must have airflow through it for the cooling to work, the PCM switches the fans on.
So suspicion must fall initially on the CHT. That is however strange as its the sensor that is also used by the PCM/ECU to generate the signal for the 'gauge' in the dash. However, my opinion is that the 'gauge' is more of a 3 zone indicator, cool - OK - too hot, not a true temperature gauge as in earlier direct driven vehicles. So the CHT could be sending an 'OK but hot' signal, which would turn fans on, but not show on the dash.
Could be investigated further using an EOBD reader and programme to monitor PCM coolant temperature, or simply replace the CHT.....
Oh, finally, some Focus have a Ford work-around for high under bonnet temperature of an 'old fashion' fan switch cable tied to the battery tray. Its directly wired to the battery so if the temperature goes over ~90, even after the engine is off, the fans come on!!
Martin
#30
There is no radiator fan switch on a Focus. The fans are turned on and off, slow speed (via (i)another(/i) resistor pack in the shroud) or high speed by 2 relays in the engine bay fuse box. These are operated directly by the PCM/ECU.
I don't know the precise logic involved, but usually assume that the primary measurement that triggers them is the Cylinder Head Temperature (CHT) sensor. Again, except in the ST170, there is no coolant temperature sensor.
The PCM, as well as being part of the aircon clutch switching, takes a signal of aircon on (demand). As the condenser in front of the radiator must have airflow through it for the cooling to work, the PCM switches the fans on.
So suspicion must fall initially on the CHT. That is however strange as its the sensor that is also used by the PCM/ECU to generate the signal for the 'gauge' in the dash. However, my opinion is that the 'gauge' is more of a 3 zone indicator, cool - OK - too hot, not a true temperature gauge as in earlier direct driven vehicles. So the CHT could be sending an 'OK but hot' signal, which would turn fans on, but not show on the dash.
Could be investigated further using an EOBD reader and programme to monitor PCM coolant temperature, or simply replace the CHT.....
Oh, finally, some Focus have a Ford work-around for high under bonnet temperature of an 'old fashion' fan switch cable tied to the battery tray. Its directly wired to the battery so if the temperature goes over ~90, even after the engine is off, the fans come on!!
Martin
I don't know the precise logic involved, but usually assume that the primary measurement that triggers them is the Cylinder Head Temperature (CHT) sensor. Again, except in the ST170, there is no coolant temperature sensor.
The PCM, as well as being part of the aircon clutch switching, takes a signal of aircon on (demand). As the condenser in front of the radiator must have airflow through it for the cooling to work, the PCM switches the fans on.
So suspicion must fall initially on the CHT. That is however strange as its the sensor that is also used by the PCM/ECU to generate the signal for the 'gauge' in the dash. However, my opinion is that the 'gauge' is more of a 3 zone indicator, cool - OK - too hot, not a true temperature gauge as in earlier direct driven vehicles. So the CHT could be sending an 'OK but hot' signal, which would turn fans on, but not show on the dash.
Could be investigated further using an EOBD reader and programme to monitor PCM coolant temperature, or simply replace the CHT.....
Oh, finally, some Focus have a Ford work-around for high under bonnet temperature of an 'old fashion' fan switch cable tied to the battery tray. Its directly wired to the battery so if the temperature goes over ~90, even after the engine is off, the fans come on!!
Martin
Matt
#31
PassionFord Post Whore!!
iTrader: (1)
What he ^^ said, although to add make sure your heater position switch is not aimed at WINDSCREEN as the A/C is on then REGARDLESS, this is why it's coloured orange but not many know this.
If the fans are on all the time this indicates a major fault has been detected unless of course it is overheating for whatever reason.
It is indeed the CHT that indirectly switches the fans, this informs the ECU of the temperature of the metal of the cylinder head directly, this info is then used to control the temp gauge and fans as well as running the engine as well.
IIRC the temp gauge is set by CAN BUS to only display half unless near overheating.
Do the fans come on when the ignition is first switched on?
If not then remove the connector of the CHT this will log a fault and bring the fans on, when re connected the fault will be no longer and the fans will turn off, this shows if the CHT is working ok.
Martin
If the fans are on all the time this indicates a major fault has been detected unless of course it is overheating for whatever reason.
It is indeed the CHT that indirectly switches the fans, this informs the ECU of the temperature of the metal of the cylinder head directly, this info is then used to control the temp gauge and fans as well as running the engine as well.
IIRC the temp gauge is set by CAN BUS to only display half unless near overheating.
Do the fans come on when the ignition is first switched on?
If not then remove the connector of the CHT this will log a fault and bring the fans on, when re connected the fault will be no longer and the fans will turn off, this shows if the CHT is working ok.
Martin
#33
Right iv noticed now that the fans only come on when the AC is on or when the heater switch is directed to the windsreen. Think someone told me on one of my posts this shud happen. Is this rite? Dont think the fans come on any other time and seems wierd how they come on everytime i have my heaters on me windsreen they come on
Matt
Matt
#34
PassionFord Post Whore!!
iTrader: (1)
First off the answer to your first post, there isn't one.
The Focus uses a NTC (Negative Temperature Coefficent) sensor which is between two of the spark plugs this measures the temperature of the metal itself and hence the running temp of the engine, this info is used by the ECU to determine the engines fuelling requirements and also for the cooling fans and the temperature gauge.
Now for the second:
The cooling fans will come on when the AC is switched on OR when the heat direction is set to windscreen REGARDLESS of blower position or AC setting, this is why the icon is orange coloured.
The cooling fans will only come on to cool the coolant due to insufficent air flow so moving in slow moving traffic or at a standstill for prolonged perioids of time.
Martin
The Focus uses a NTC (Negative Temperature Coefficent) sensor which is between two of the spark plugs this measures the temperature of the metal itself and hence the running temp of the engine, this info is used by the ECU to determine the engines fuelling requirements and also for the cooling fans and the temperature gauge.
Now for the second:
The cooling fans will come on when the AC is switched on OR when the heat direction is set to windscreen REGARDLESS of blower position or AC setting, this is why the icon is orange coloured.
The cooling fans will only come on to cool the coolant due to insufficent air flow so moving in slow moving traffic or at a standstill for prolonged perioids of time.
Martin
#35
Now for the second:
The cooling fans will come on when the AC is switched on OR when the heat direction is set to windscreen REGARDLESS of blower position or AC setting, this is why the icon is orange coloured.
The cooling fans will only come on to cool the coolant due to insufficent air flow so moving in slow moving traffic or at a standstill for prolonged perioids of time.
Martin
The cooling fans will come on when the AC is switched on OR when the heat direction is set to windscreen REGARDLESS of blower position or AC setting, this is why the icon is orange coloured.
The cooling fans will only come on to cool the coolant due to insufficent air flow so moving in slow moving traffic or at a standstill for prolonged perioids of time.
Martin
#38
Ford Focus blower - Help!
I have just purchased a 2002 ford focus 1.6 zetec, I have no blowers at all. I started at the bottom and checked the fuses under the bonnet and found a 30 amp blown, I replaced this hoping this would remedy my problem position 1 2 and 3 nothing happens.... Posistion 4 nothing happens but the fuse blows! I have just purchaed a new resistor pack as advised by the nice man at fords. Still nothing on position 1 2 and 3 and position 4 nothing happens but the fuse pops!! Can somebody please advise the next step to try and remedy this fault? I have read the motor may be seized so I removed the power supply to the motor and the fuse's still popped at position 4. Any advice would be appreciated.
Thanks in advance.
Thanks in advance.
#39
PassionFord Regular
If the fuse is blowing with the motor totally disconnected, I would suggest there is a fault in the GN/OG wire from the fuse, via C78.
If you check the contact in the motor plug is it open circuit or shorted to ground.
See the circuit diagram further up this thread.
Martin
If you check the contact in the motor plug is it open circuit or shorted to ground.
See the circuit diagram further up this thread.
Martin