Cooling fan not working

Tiny
MATT25
  • MEMBER
  • 2001 JEEP CHEROKEE
I've checked this site and many others and cannot find an answer to my problem. My cooling fan will not run. I've checked the motor by wiring it to the battery - it runs fine. I've checked the fuses - they're fine. I've replaced the relay in the the main fuse box in the engine - it's fine. And I've even replaced the temp. Sensor in the thermostat housing. Nothing seems to fix it. Although, when I first replaced the relay, the fan rand for a few minutes then stopped. I rechecked everything and it's all still good. Is there another relay or temp. Sensor that I might be missing? Does the 2001 cherokee have a 2nd relay behind the headlight like the grands do?

The temp sensor in the thermo housing, it has two wires. Which one would I ground? If you're not talking about that one, where is the other one? I've read (haynes manual and other sources) that the temp sensor that controls the fan is in the engine block near the back left corner (closest to the driver). If it is there, I can't see it and would have a heck of a time replacing it because of the intake and exhaust manifolds. I will buy a retractable mirror and see if it's there, but I have been under and can't see any wires leading to that area. I think this particular in-line six cylinder engine doesn't have one there, but I could be wrong. I just wanted to get more information before I go removing a bunch of other parts just to see.

I never let it go too long (gas and all), but as I mentioned in my last comment, the temp. Gauge will slowly rise above normal temp. At idle. This is a concern only if I get stuck in traffic on a hot day. The highest I let it get was around 210-220 degrees F. I know it's unlikely that it will fully overheat, but I'm certain that when the temperature gets too high, the electric fan should kick on to support the belt-fan. Why else would it be on there? In my limited experience, A/C has only caused electric fans to switch on sooner (because of the extra cooling required for the condenser), but I've never heard of one existing only for the A/C system. Either way, I was planning on getting the A/C fixed next. Perhaps that will solve the problem, but it seems unlikely given what I know at this point. I appreciate your help on this. Any idea about whether it could be the radiator fan relay control in the powertrain control module. I don't know exactly where that is, but I see it in this diagram, and I'm sure I could find it. I've heard of other folks having to get a $50 relay switch for their cooling fan on comparable jeep models, but the one I replaced was a $10 one. I don't know if that matters, but is there a 2nd relay?

It does have two fans. The air conditioning isn't working right now. It's not leaking because the pressure is still good (I tried adding some 134a and it didn't take any). The clutch on the compressor doesn't engage. I thought this was a separate problem and was going to deal with it later. I've heard that the electric fan should eventually kick on at idle (because the belt-driven fan is only adequate at 25 mph or greater). If I leave it at idle, the temp gauge does keep creeping up, so shouldn't the electric fan kick on?

Also, a diagram would be helpful (I couldn't find an accurate one anywhere). I went back and checked the 15 amp fuse in the kick panel (still good). I don't know what the problem is. If it were set to only run when the ac is on, wouldn't there be a limiter or switch for that? I don't see one in the diagram. Could it be the Radiator fan relay ctrl (powertrain control module in the left fender side shield)? That's the only thing I haven't checked and cleared. I didn't even know about it.

Any help will be appreciated.

Thanks
-M
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Wednesday, July 22nd, 2009 AT 1:28 AM

33 Replies

Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
There is a radiator cooling fan relay that goes bad in these cars. Here is a guide and some radiator cooling fan wiring diagrams (below) so we can do some testing to find out what the problem is. the cooling fan relay is located at the front near the radiator on the right side.

Here is three guides that will help us get it fixed.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/how-to-check-a-car-fuse

What is making you worried about your fan not coming on? is the engine overheating There are many cars that the electrical fan does not come on until the temp gets to 220 230 and some cars do have a completely separate fan that only comes on for the AC.

(Check out the diagrams below)

Please run some tests and get back to us.

Cheers
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Saturday, July 25th, 2009 AT 11:09 PM
Tiny
MATT25
  • MEMBER
  • 2 POSTS
Then why did the electric fan run for 5 min immediately after I first changed the relay? It hasn't run since. That makes no sense, especially if the fan doesn't come on unless the A/C is on. Let me clarify, the 210-220 degrees, was according to the temp gauge, it was in the process of climbing slowly when I shut it off. Anyone can open the engine compartment on this jeep and feel that it's definitely running hotter than it should. I'm worried that this will, overtime, fatigue vital parts and cause problems down the road. And of course, a hot day and heavy traffic could be problematic. The fact that the fan ran the instant I put in the relay, shutoff after a few minutes, and hasn't run since should mean that something isn't working properly. I suspected that the new relay just burnt out, which is why I put in a third one, but the fan didn't run that time. So I replaced the fan motor because someone told me the fan motor can pull to much amperage causing the relay to go out. So I replaced the relay again and the system has been fine ever since.

Thanks for the help 2carpros! I love this site
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Sunday, July 26th, 2009 AT 9:48 AM
Tiny
BIGDANO
  • MEMBER
  • 1 POST
  • 2001 JEEP CHEROKEE
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 125,000 MILES
2001 jeep cherokee, cooling fan will not come on replaced fuses, relay and sensor
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Monday, May 29th, 2017 AT 3:57 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
Try jumping power directly to it to test the fan motor. If the motor is good, test the inputs to the relay.
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Monday, May 29th, 2017 AT 3:57 PM (Merged)
Tiny
MSLYNETTE
  • MEMBER
  • 1 POST
  • 2001 JEEP CHEROKEE
Engine Cooling problem
2001 Jeep Cherokee 6 cyl Four Wheel Drive Automatic

my fan stop working causing my AC to stop blowing to
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Monday, May 29th, 2017 AT 3:57 PM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Check fuses and relay
check coolant fan motor
most common is fan module relay
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Monday, May 29th, 2017 AT 3:57 PM (Merged)
Tiny
JEEPSTER
  • MEMBER
  • 1 POST
  • 1998 JEEP CHEROKEE
The symptoms I am having:

- Electric cooling fan does not come on when idling in hot weather
- Temperature guage always at the same level when hot - just below halfway mark
- Fan sounds like it is working overtime when accelerating

I have changed the thermostat and checked the coolant, both are good.
I don't have problems with overheating but am concerned that the electric fan is not coming on and that it always sounds like it is in warm up mode (fan working very hard)
I tried running it with the RPM's high on a hot day to see if the fan woul d come on but it didn't and the temp guage would not budge. I checked the coolant shortly after but it was cool? The top rad hose is very hot but I could put my finger in the coolant afetr removing the rad cap

Anyone have any suggestions?
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Monday, May 29th, 2017 AT 3:57 PM (Merged)
Tiny
DEMEARSJR
  • MECHANIC
  • 110 POSTS
Could be either the coolant sensor or the cooling fan switch
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
RYBACK007
  • MEMBER
  • 1 POST
  • JEEP CHEROKEE
The engine cooling fan dosen't run not even with the A/C on it is a 2003 Jeep grand cherokee 6 cyl
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
FISHERMAN
  • MECHANIC
  • 938 POSTS
Hello !

Start checking the fuses if good check the fan relay.

If you find a blown fuse check for loose conn. Or faulty fan motor.

Let us know and good Luck!
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
SERGIE1047
  • MEMBER
  • 1 POST
  • 1999 JEEP CHEROKEE
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 78,000 MILES
Engine Cooling problem
1999 Jeep Cherokee 6 cyl Two Wheel Drive Automatic 78000 miles

My jeep fan cooling is not working but it is not overheating only smell something burn. I replaced the temperature sending switch and the cooling fan relay. Now my engine light is always on, try to disconnect the battery it work for few days and the engine light check is back again. Please tell me what to do before I go to the shop or the dealer. I want to fix this if I can do it by myself. I appreciate any help. Thank you Sergie Hernandez
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Could be faulty engine coolant temp sensor. Since engine light is on, take to local auto part store and ask them to scan your vehicle for trouble codes. Most auto part stores do this for free.
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
EDWARD.S
  • MECHANIC
  • 166 POSTS
Hi, First Thing To Check Is The Fuse To the Cooling fan. If That is Good, See If the Cooling fan Comes On When You Put On the a/c. If It Does come On The Fan motor Is ok. There Is A fan module That goes bad In jeeps At the time, That Module Is a dealer Item. Only. That module Is Behind The right Front headlight, On the Fender well. Sometimes It Is better to Remove the Front Bumper To Get Access to it. There Is a test in the Snap On Modis Scanner For it. To Turn It off and on.

Hope This Helps you,
Good luck
Edward S.
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
RBILLUPS
  • MEMBER
  • 1 POST
  • 2003 JEEP CHEROKEE
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 100,000 MILES
Engine Cooling problem
2003 Jeep Cherokee 6 cyl Two Wheel Drive Automatic 100000 miles

Engine runs hot because radiator fan does not come on. Fan works when I wire it directly to the battery. Also the fuse is ok and I changed the temp senor. What is causing the fan not to come on?
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
INTERNETMECHANIC
  • MECHANIC
  • 700 POSTS
Check for trouble codes. If you do it yourself, at the least, you need an obd2 code reader. Check the circuits at the fan relay.
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
MISTYTERRY
  • MEMBER
  • 1 POST
  • 2002 JEEP CHEROKEE
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 125,455 MILES
Engine Cooling problem
2002 Jeep Cherokee 6 cyl Two Wheel Drive Automatic 125455 miles

My Jeep is over heating because the fan is not coming on. What are some things I can check? Will a code reader tell me what is wrong?
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Code reader will help if you have check engine light
if you have check engine light on
try and cycle key on off on off on read codes in odometer area
most likely and common is coolant fan relay module under right side headlight and battery
good luck

*****************************************
need manual CHECK IT @
https://www.2carpros.com/kpages/auto_repair_manuals.htm
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
DEFLEPCHICK69
  • MEMBER
  • 2 POSTS
  • JEEP CHEROKEE
2002 Jeep Grand Cherokee Sport 65,000 miles. Cooling fan will not work. We have checked the fuses and they are fine. Can you please help?
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
SKIPPYTCG
  • MEMBER
  • 8 POSTS
I feel your pain on this one. My 1999 jeep cherokee sport, 4.O l with 99k on it has the same problem. If you get an answer to this let me know.
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Monday, May 29th, 2017 AT 3:58 PM (Merged)
Tiny
DEFLEPCHICK69
  • MEMBER
  • 2 POSTS
We got mine fixed yesterday. It turned out to be the relay. We had to take off the front bumper and grill to get to it, but we did and it was the relay. Hope that helps.
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Monday, May 29th, 2017 AT 3:58 PM (Merged)

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