• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Stock e-fan won't come on

B

Ben824

NAXJA Forum User
Location
Woodstock, GA
Ok so I have been having an issue with my electric fan. It just quit one day and won't come on at all. Not if the A/C is on or if the temp jumps up to where it is supposed to kick on. The check engine light is on and I had the code pulled at Autozone and they said the code was for the fan relay. I replaced it and nothing changed. I swapped it with the fuel pump relay, knowing it worked, and still nothing, and the fuel pump runs fine with the replacement relay. So the relay is not the issue. I checked the big fuse and it is fine and there isn't any corrosion on the contacts.

I have never messed with anything with the electric fan other than removing it to replace the radiator which after a few leaky champions I removed it a few times and it has never caused a problem. I also removed it when I had to replace the high pressure power steering hose just to make it easier to do the job.

Could this be a problem with the computer? I'm stumped here.
 
Assume '97? E-fans are triggered in different ways for different years.

Start as suggested by hooking fan leads to a 12 volt source.

Also unplug the connector to the temp sensor on the thermostat housing to see if fan comes on.
 
Oh wow can't believe I left the basics out. Yes it's a 97 XJ 4.0L auto 4x4 Country model.

I have confirmed that the fan does indeed still work. Haven't tried unplugging the temp sensor yet. I'll give it a try.

Any other ideas?
 
Interesting. I was just going to edit with thought that unplugging the connector probably won't do anything since you have a code, but it can't hurt to go ahead and try that.
 
Over time, carbon builds up in the motor causing several problems. Sometimes the electric fan starts running erratically, like it does not always want to start. Sometimes, when you turn them by hand, you will feel them "cog". By this I mean that it feels like it is going past notches. A DC motor should turn smoothly.

Here is how to reclaim a 97+ Fan Motor after removing the assembly from the XJ.
1. Remove the C-Clip and metal spacer securing the blade to the motor.
2. Remove the blade from the shaft. Tap the motor shaft LIGHTLY to get it off. DO NOT PRY ON THE BLADES, THEY WILL SHATTER!!!!!!
3. Remove the three screw securing the motor to the shroud.
4. There are several tabs that are bent down holding the backing plate. Gently pry these up to release the backing plate.
5. Blow out the built up carbon dust from the inside of the motor. As the motor operates, the brushes wear depositing carbon everywhere. This shorts the segments causing the "Cog" feel.
6. Gently clean between the commutator segments to remove the carbon. A very small scribe works well.
7. Reattach the backing plate by gently bending the tabs back into place.
8. Reattach motor to shroud.
9. Reattach blade.
10. Test.

This is a, usually, one time repair as the tabs holding the back plate on tend to snap off with repeated bending as they are just thin sheet steel. It is also possible to just buy the motor by itself. Google the part number that is printed on the motor. It is a Bosch Part.
 
I had a similiar problem on my 2000. The elec fan didn't come on no matter what. I first verified the fan worked by hooking it to the battery with wires, good there.

I then found a leak in the AC system, when I repaired the leak and the system was fully charged my elec fan has been working just fine.

Worth checking.
 
O-Gauge Steamer said:
Over time, carbon builds up in the motor causing several problems. Sometimes the electric fan starts running erratically, like it does not always want to start. Sometimes, when you turn them by hand, you will feel them "cog". By this I mean that it feels like it is going past notches. A DC motor should turn smoothly.

Here is how to reclaim a 97+ Fan Motor after removing the assembly from the XJ.
1. Remove the C-Clip and metal spacer securing the blade to the motor.
2. Remove the blade from the shaft. Tap the motor shaft LIGHTLY to get it off. DO NOT PRY ON THE BLADES, THEY WILL SHATTER!!!!!!
3. Remove the three screw securing the motor to the shroud.
4. There are several tabs that are bent down holding the backing plate. Gently pry these up to release the backing plate.
5. Blow out the built up carbon dust from the inside of the motor. As the motor operates, the brushes wear depositing carbon everywhere. This shorts the segments causing the "Cog" feel.
6. Gently clean between the commutator segments to remove the carbon. A very small scribe works well.
7. Reattach the backing plate by gently bending the tabs back into place.
8. Reattach motor to shroud.
9. Reattach blade.
10. Test.

This is a, usually, one time repair as the tabs holding the back plate on tend to snap off with repeated bending as they are just thin sheet steel. It is also possible to just buy the motor by itself. Google the part number that is printed on the motor. It is a Bosch Part.
Click to expand...

Tried two different fans both came on connected directly to the battery but will not come on when connected to the factory harness. So fans are good and it is something else.
 
Boudroux said:
I had a similiar problem on my 2000. The elec fan didn't come on no matter what. I first verified the fan worked by hooking it to the battery with wires, good there.

I then found a leak in the AC system, when I repaired the leak and the system was fully charged my elec fan has been working just fine.

Worth checking.
Click to expand...

Was your AC system still blowing cold? Mine still blows cold air fine.
 
I am running two factory e-fans and deleted the factory clutch fan. I have put together my own autonomous wiring harness for the new passenger side fan. It is completely stand alone except for the one trigger wire to turn on the system when the vehicle is started. Think of this wire as like the remote wire for an aftermarket audio amp. It's to trigger the main power relay. It is triggered off of the fuel pump relay so that it comes on when the vehicle is on. Now this new fan has it's own two stage speed setup being trigger by a BMW two stage temp switch.

But all that aside it's completely seperate from the rest of the Jeeps wiring and it never caused a problem with the OEM driver side fan. In fact the entire system worked flawlessly with these two fans. But it can allow the Jeep begin to overheat slightly in stop and go traffic situations. So the Jeep has crept up to where the OEM drivers side fan should kick on, which it would before all this happened. As soon as the OEM fan kicked on these two fans running the temps dropped back down rapidly. In fact if I would run the AC I ran just below 210 even better than with the AC off.
 
Ben824 said:
Was your AC system still blowing cold? Mine still blows cold air fine.
Click to expand...

It was still blowing cold and didn't indicate a problem however thinking back the AC compressor didn't cycle normaly so the pressure had to have been down enough for that to happen. I just happened to notice a small green bubble one day while pulling the tranny dip stick while the air was on.

After doing some reading I learned the fan relay is triggered by the AC system, in addition to other stuff. Where I live I run ac a large part of the year so I immediately took it in for a repair and that took care of the fan issue also.

Funny thing is after the repair my AC doesn't seem to blow as cold but the darn fan turns on like it should. :laugh:
 
Not to hijack, but quick question.
Whats factory electric fan pull amp wise? Using search brought back lots of conflicting answers.
 
pipewrench said:
Not to hijack, but quick question.
Whats factory electric fan pull amp wise? Using search brought back lots of conflicting answers.
Click to expand...

Not sure but when researching to do my mechanical fan delete, I read where a lot of people tried running a stock e-fan and the taurus fan with a 30 amp relay and blowing them, so I went to Napa and said I need a 70 amp relay. It took some looking and a couple phone calls and he found one. I have no idea if it is universal or specific or what the part humber is off the top of my head but it works great!
 
The ECU can only "see" issues in the fan circuit as far as the coil side of the relay. It can't tell if the relay is actually closing or the fan is actually running... so since you've already verified the relay is fine, I suspect the wiring between the relay and the ECU, or the relay socket, or the ECU.

Did you unplug the temp sensor to test yet? You'll get a DTC from this, but the fan should come on basically instantly if you do this.
 
You must log in or register to reply here.

Similar threads

Ecomike
87 Renix XJ No fuel, No brake lights, cranks fine
2
Replies
27
Views
847
Anak
Anak
V
High temp woes
2
Replies
21
Views
391
Vitzaa
V
R
Fan not turning on when hot- fan works!
Replies
2
Views
2K
JMA_2001XJ
J
F
99 XJ V8 Swapped, now door's will unlock but won't lock
Replies
3
Views
144
FreeRoller16
F
M
Installing heated factory seat
Replies
3
Views
833
mortenhj
M
Back
Top