Cooling fans not turning on
#1
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2002 XJ Sport
I have read from the x100 people that the cooling fans should turn on at 205 fahrenheit. If that is the case, mine don't turn on. Not even at 220 fahrenheit. So obviously something is up. Now, when I turn on the AC, only the left fan turns on.
Diagnostics I have done:
Number 12 and 14 30A fan fuses are good. Test light used for that.
Left fan motor connector(PCM side) has power on terminal A(tested with test light)
But the right side, passenger fan connector(PCM side) doesn't light the test light from either terminal A or B.
What should I do next?
I have read from the x100 people that the cooling fans should turn on at 205 fahrenheit. If that is the case, mine don't turn on. Not even at 220 fahrenheit. So obviously something is up. Now, when I turn on the AC, only the left fan turns on.
Diagnostics I have done:
Number 12 and 14 30A fan fuses are good. Test light used for that.
Left fan motor connector(PCM side) has power on terminal A(tested with test light)
But the right side, passenger fan connector(PCM side) doesn't light the test light from either terminal A or B.
What should I do next?
#2
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Try checking fuse in Engine Management Fuse Box, which will be located in same enclosure as PCM, its # 14 10A. See wiring diagram attached. There is also a fan relay module that sits adjacent to LH crush tube behind bumper. You can access this from under the vehicle, or going through the wheel arch liner. Below is a picture from an earlier model XJ - but will be in same location.
If everything checks out, most likely the motor for that fan has failed and will need to be replaced.
If everything checks out, most likely the motor for that fan has failed and will need to be replaced.
![](https://www.jaguarforums.com/forum/attachments/xj-xj6-xjr6-x300-26/70590d1390941088-fan-relay-fan-relay.jpg)
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#3
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At the fan control module you can read the resistance through both fans and they should be the same , negating it's not froze up and won't turn freely . I found water inside my fan control module and couldn't repair . As a last try you can cut the fan lead wires and hook up to a battery charger provided it produces enough amps .
Notice one fan leg is power seeking and the other fan leg is ground seeking at the FCM and is the other way around for the other fan
Notice one fan leg is power seeking and the other fan leg is ground seeking at the FCM and is the other way around for the other fan
Last edited by Lady Penelope; 01-29-2018 at 04:56 PM.
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Z07Brandon (01-29-2018)
#4
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#5
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TLDR you have a dead fan motor or a bad connection somewhere.
From another recent thread:
From another recent thread:
Both fans should always run together. The fans will kick on HIGH when the aircon compressor is engaged (and some other conditions maybe, if coolant is above 40c or something to do with ambient temp, don't recall for sure but it's in the climate control documentation somewhere). They will kick on LOW when the coolant is slightly above the nominal operating temp (and AC compressor isn't engaged), and HIGH if the coolant temp gets a certain amount above that. LOW just runs the fans in series to run each at 6v, so if you have an open circuit in one motor you may only get HIGH operation.
The motors do give out sometimes, I had a dead one when I got my car. It could also be a wiring fault going to the fan. It's pretty easy to remove the fan shroud and test each motor independently.
The motors do give out sometimes, I had a dead one when I got my car. It could also be a wiring fault going to the fan. It's pretty easy to remove the fan shroud and test each motor independently.
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Z07Brandon (01-29-2018)
#6
#7
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At the fan control module you can read the resistance through both fans and they should be the same , negating it's not froze up and won't turn freely . I found water inside my fan control module and couldn't repair . As a last try you can cut the fan lead wires and hook up to a battery charger provided it produces enough amps .
Notice one fan leg is power seeking and the other fan leg is ground seeking at the FCM and is the other way around for the other fan
Notice one fan leg is power seeking and the other fan leg is ground seeking at the FCM and is the other way around for the other fan
Where I bolded your text, are you saying since I didn't get power from either terminal on the left side fan connector, that it is ok?
Can the module be opened up without destroying to see if water got into it?
IMO, the problem is two things. 1, the fans don't turn on when they should. 2, right fan not working. Sorry for all the novice questions.
But tomorrow, I'll remove the fan shroud and feed power to both motors, especially the right fan motor. The blades do spin freely.
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#8
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The wiring guide is hard to follow but you can remove the suspect right fan and plug it into the left side and turn on the A/C being very careful of the spinning blades . Much easier if the left is suspect as you can bring the longer right wires over to the installed left . Or bring it out on the ground and hook up to the battery with jumper cables . Can't remember the connector style but if it's blade and receptacle you can get those terminals at the parts store to not arc the current connector's blades or sockets .
To see inside the relay module you have to saw it open , so it would be the last thing to do
To read the module without a meter look at the 2 wire fan connector . Once commanded to spin one wire will test with your test lamp to car ground and the other wire will test from a positive power source ( maybe the fuse box terminal ) as the relay provides a ground .
Right fan :
Orange / Green wire will be powered provided by the relay module when commanded on
test light to ground
Black wire will always be a car bolt ground test light from power source
Left fan :
Brown / Light Green wire will always have power from the fuse test light to ground
Orange / Yellow wire will have a ground provided by the relay module when commanded ontest light from power source
Best to try the one that works to get the hang of it and not lose confidence .
Any questions , just ask
After you get those test result we'll go further as to not put to much info out yet and cloud things up as there is some cloudy interpretation of what action to take .
I can't speak French
To see inside the relay module you have to saw it open , so it would be the last thing to do
To read the module without a meter look at the 2 wire fan connector . Once commanded to spin one wire will test with your test lamp to car ground and the other wire will test from a positive power source ( maybe the fuse box terminal ) as the relay provides a ground .
Right fan :
Orange / Green wire will be powered provided by the relay module when commanded on
test light to ground
Black wire will always be a car bolt ground test light from power source
Left fan :
Brown / Light Green wire will always have power from the fuse test light to ground
Orange / Yellow wire will have a ground provided by the relay module when commanded ontest light from power source
Best to try the one that works to get the hang of it and not lose confidence .
Any questions , just ask
After you get those test result we'll go further as to not put to much info out yet and cloud things up as there is some cloudy interpretation of what action to take .
I can't speak French
Last edited by Lady Penelope; 01-29-2018 at 10:59 PM.
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someguywithajag (04-26-2021)
#9
#10
#11
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If you put a paper clip in the A/C pressure switch connector you may get both fans without having to remove the fan connectors and leaving them in the original position . This would prove the A/C pressure switch is bad that command the FCM to turn on the left and right fans . Pressure switches do go bad . We are testing the fans in the A/C mode for now and not the engine coolant temp mode which may or may not be fine .
there is a odd fuse that controls this ( not a fuse but a need to have the key on to provide a ground )
On the A/C pressure switch 5 wire connector :
Blue to Black / Pink
White / Blue to White
Red / White to White
These separate jumpers on that connector one at a time will give you different left and right ( as both ) fans to be commanded on through the FCM
there is a odd fuse that controls this ( not a fuse but a need to have the key on to provide a ground )
On the A/C pressure switch 5 wire connector :
Blue to Black / Pink
White / Blue to White
Red / White to White
These separate jumpers on that connector one at a time will give you different left and right ( as both ) fans to be commanded on through the FCM
Last edited by Lady Penelope; 01-30-2018 at 09:41 AM.
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someguywithajag (04-26-2021)
#12
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So this is what I just did. Disconnected both fan connectors, and connected the right fan connector to left fan. AC on and it was powering the fan. Bad fan motor?
For what it's worth I turned the AC on at around 205 degrees Fahrenheit. With it on, the fan wasn't constantly blowing, it was more an on off thing. But nonetheless, it did turn it on.
Edit: Lapy P is correct, left fan wiring to small to get it to the right side. That's why I put the right fan wiring on the left side.
For what it's worth I turned the AC on at around 205 degrees Fahrenheit. With it on, the fan wasn't constantly blowing, it was more an on off thing. But nonetheless, it did turn it on.
Edit: Lapy P is correct, left fan wiring to small to get it to the right side. That's why I put the right fan wiring on the left side.
Last edited by Z07Brandon; 01-30-2018 at 11:32 AM.
#13
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With the same test setup you saw the left fan spin then bringing the right connector to the left saw the left spin again ?
If not then jumper the A/C pressure switch connector in the normal fan connector positions .
As it functions the A/C may not be getting to a high enough pressure to make the switch close in the natural operation to give you the right fan .
The simplest thing would be to power up the right fan with a battery charger or the battery itself but that only test the fan only .
If not then jumper the A/C pressure switch connector in the normal fan connector positions .
As it functions the A/C may not be getting to a high enough pressure to make the switch close in the natural operation to give you the right fan .
The simplest thing would be to power up the right fan with a battery charger or the battery itself but that only test the fan only .
Last edited by Lady Penelope; 01-30-2018 at 11:59 AM.
#14
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With the same test setup you saw the left fan spin then bringing the right connector to the left saw the left spin again ?
Yes correct.
If not then jumper the A/C pressure switch connector in the normal fan connector positions .
As it functions the A/C may not be getting to a high enough pressure to make the switch close in the natural operation to give you the right fan .
The simplest thing would be to power up the right fan with a battery charger or the battery itself but that only test the fan only .
Yes correct.
If not then jumper the A/C pressure switch connector in the normal fan connector positions .
As it functions the A/C may not be getting to a high enough pressure to make the switch close in the natural operation to give you the right fan .
The simplest thing would be to power up the right fan with a battery charger or the battery itself but that only test the fan only .
#15
#16
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Took a pic of the inside of mine but is somewhere in my computer . What is inside is 4 brushes , and a noise capacitor with 2 chokes .
At 110 K miles I have alot of brush material left
https://www.ebay.com/itm/Jaguar-Radi...ZZYmZU&vxp=mtr
At 110 K miles I have alot of brush material left
https://www.ebay.com/itm/Jaguar-Radi...ZZYmZU&vxp=mtr
Last edited by Lady Penelope; 01-30-2018 at 06:35 PM.
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Z07Brandon (01-30-2018)
#17
#18
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#19
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