LOST JEEPS :: View topic - Radiator Fan - Never Comes On? How Can I Test It?

NUMBER: 08-043-05
GROUP: Electrical
DATE: August 11, 2005

THIS BULLETIN IS BEING PROVIDED IN ADVANCE. DO NOT PERFORM ANY
ACTIONS RELATED TO THIS BULLETIN UNTIL AUGUST 26, 2005. THE DRB III
SOFTWARE VERSION MUST BE AT LEVEL 62.2 TO PERFORM THIS BULLETIN. THE
DRB III SOFTWARE WILL BE AVAILABLE ON TechCONNECT BY AUGUST 26, 2005.
FOR MARKETS OUTSIDE OF THE UNITED STATES AND CANADA, THE DRB III
VERSION 62.2 SOFTWARE WILL BE AVAILABLE ON CINONConnect AND
TechCONNECT BY AUGUST 26, 2005. THE DRB III VERSION 62.2 SOFTWARE WILL
ALSO BE AVAILABLE ON THE ITIS DVD SEPTEMBER 2005 RELEASE.
SUBJECT:
Engine Temperature Gauge - Indicator Reads A Higher Temperature Than Actual
OVERVIEW:
This bulletin involves reprogramming the instrument cluster control (CCN)
module.
MODELS:
2005 (KJ) Liberty / Cherokee
NOTE: This bulletin applies to vehicles equipped with a 2.8L turbo diesel
engine
(sales code ENR).
SYMPTOM/CONDITION:
The customer may notice that the engine temperature gauge may indicate that
the engine
temperature is high. In hot ambient temperatures, and under certain driving
conditions of
extended uphill driving while towing a trailer, the engine temperature
indicator may indicate
slightly above the 3/4 normal operating temperature mark on the temperature
gauge (but
below the engine hot temperature markings). This condition may be caused by
an incorrect
calibration of the of the engine temperature gauge.
New CCN module software corrects the old engine temperature gauge
calibration.
DIAGNOSIS:
If the engine and the cooling system are operating correctly, and the above
condition is
present, then perform the Repair Procedure.
SPECIAL TOOLS/EQUIPMENT REQUIRED:
CH6000A Scan Tool (DRBIII®)
NUMBER: 08-043-05
GROUP: Electrical
DATE: August 11, 2005
CH7000A/7001A J1962 Cable with red DRBIII® connector
REPAIR PROCEDURE:
NOTE: Before proceeding verify that the DRBIII® software version is at level
62.2.
1. Connect the DRBIII® to the vehicle Data Link Connector (DLC)
2. Turn the ignition switch to the "ON" position.
3. Using the DRBIII® scan tool recalibrate the instrument temperature gauge.
a. Select "DRBIII® Standalone"
b. Select "1998 - 2006 Diagnostics"
c. Select "All (Except Below)"
d. Select "Body Interior"
e. Select "Electro/Mech Cluster (MIC)"
f. Select "Miscellaneous"
g. Select "Recalibrate Temp Gauge" option.
4. If the recalibration of the instrument cluster was successful, the
DRBIII® will display
the following message: "Recalibration Successful".
5. If the version level of the original instrument cluster software allows
recalibration, but
the recalibration of the instrument cluster was NOT successful, then the
DRBIII® will
display one of the following messages: "Recalibration Failed" or "Write To
Memory
Address Failed". If one of these messages occurs repeat the above steps.
6. If the instrument cluster has already been recalibrated to the correct
software version
level, then the DRBIII® will display the following message: "Gauge Already
Recalibrated - Press Any Key to Exit".
7. The DRBIII® will display the following message if the original instrument
cluster
software version level is not the correct version level for recalibration:
"MIC Software
Version Incorrect - Press Any Key to Exit".
8. Verify that the instrument cluster engine temperature gauge has been
recalibrated by
selecting the "Recalibrate Temp Gauge" option again. The DRBIII® should
display the
following message: "Gauge Already Recalibrated - Press Any Key to Exit".
9. Turn the vehicle ignition switch to the "OFF" position
10. Disconnect the DRBIII® from the vehicle DLC.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation
No:
Description Amount
08-45-10-94 Reprogram Instrument Cluster Control (CCN)
Module - 2.8L Turbo Diesel Engine Only
0.2 Hrs.
FAILURE CODE:
AM Authorized Modification

² Engine Temperature Message - Each time the cluster receives a message from the PCM indicating the
engine coolant temperature is within the normal operating range [up to about 124° C (255° F) for gasoline
engines, or about 110° C (230° F) for diesel engines], the gauge needle is moved to the actual relative temperature
position on the gauge scale.
² Engine Temperature High Message - Each time the cluster receives a message from the PCM indicating the
engine coolant temperature is high [above about 127° C (260° F) for gasoline engines, or 112° C (233° F) for
diesel engines], the gauge needle is moved into the center of the red warning zone on the gauge scale.
² Engine Temperature Critical Message - Each time the cluster receives a message from the PCM indicating
the engine coolant temperature is critical [above about 132° C (269° F) for gasoline engines, or 115° C (239°
F) for diesel engines], the gauge needle is moved to the high end of the red warning zone on the gauge scale.

For the gasser, the spread between normal and hot is 5 degrees F and 14f for critical. Our diesels it is 3 degrees between normal and hot and 9 degrees normal and critical. The span is tighter.

To test the following:
1) Temp sending unit measure the cylinder head next to the sending unit with engine warmed up and gauge reading normal and record. If the thermometer reads normal with the gauge at hot or critical, the sending unit, Body control Module or gauge is the problem.
2) Engine warmed up, measure the radiator top inlet and lower outlet and record the difference. If the two readings are very close when the gauge reads hot, the radiator is the problem.
3) Engine warmed up, measure the head temp near temp sensor and the engine outlet pipe where the upper radiator hose is attached and record. If the difference between cylinder head reading and the engine outlet pipe reading climbs when the gauge reads hot, the thermostat is not fully opening or there is a restriction in the cooling system.

From the service manual.
E fan turns on when the PCM feel s like it. Many inputs including battery temperature !?!!?

The electric radiator cooling fan is controlled by the Powertrain Control Module
(PCM) through the radiator cooling fan relays. The PCM regulates fan operation
based on input from the engine coolant temperature sensor, battery temperature
sensor, air conditioning select switch and vehicle speed.
The fan is not energized during engine cranking regardless of the electrical input
from the temperature sensors and air conditioning switch. However, if engine
operation conditions warrant fan engagement, the fan will run once engine starts.
On vehicles NOT equipped with AC: The relay is energized when the coolant
temperature is above 80° C (176° F), or battery temperature sensor above -12° C
(10° F). It will then de-energize when coolant temperature drops below 82° C
(180° F), or battery temperature sensor below -9° C (16° F).
Vehicles Equipped with AC: In addition to using coolant temperature and
battery temperature sensor to control cooling fan operation, the cooling fan will
also be engaged when the air conditioning system is activated. The relay is also
energized when air conditioning is selected and coolant temperature is above 95°
C (203° F), or, air conditioning is selected and battery temperature sensor is
above 41° C (106° F). It will then de-energize when air conditioning is selected
and coolant temperature is below 92° C (198° F), or air conditioning is selected
and battery temperature is below 38° C (100° F).
MITCHELL 1 ARTICLE - 2006 ENGINE Cooling - Liberty Page 1 of 1
http://

Author:	mitchell [ Mon Apr 13, 2009 2:16 am ]
Post subject:	Radiator Fan - Never Comes On? How Can I Test It?
Hello, I have had my 2006 Liberty CRD for about nine months and the radiator cooling fan has never come on. The only time the temperature gauge has passed mid-mark was when I was towing a tiny camper into a head wind. I slowed down and the temperature gauge dropped back to below the halfway mark. I do not think that the exact position of that gauge is determinant of anything other than an increase or decrease from its normal position. I have never driven any vehicle that had a fan clutch where the fan did not at least come on sometimes. How can I test the fan to see if it is working? I am slow to ask the dealer first because since I still have warranty, they always want to replace parts when I've gone in and a couple of times it was seemingly unnecessary. I'd rather not have them disassemble things to get to that fan if it is not broken. Mitchell

Author:	BlackLibertyCRD [ Mon Apr 13, 2009 6:52 am ]
Post subject:	Re: Radiator Fan - Never Comes On? How Can I Test It?
mitchell wrote: Hello, I have had my 2006 Liberty CRD for about nine months and the radiator cooling fan has never come on. The only time the temperature gauge has passed mid-mark was when I was towing a tiny camper into a head wind. I slowed down and the temperature gauge dropped back to below the halfway mark. I do not think that the exact position of that gauge is determinant of anything other than an increase or decrease from its normal position. I have never driven any vehicle that had a fan clutch where the fan did not at least come on sometimes. How can I test the fan to see if it is working? I am slow to ask the dealer first because since I still have warranty, they always want to replace parts when I've gone in and a couple of times it was seemingly unnecessary. I'd rather not have them disassemble things to get to that fan if it is not broken. Mitchell Turn on the A/C and step to the front of the vehicle and the electric fan should run with the compressor.

Author:	CRDMiller [ Mon Apr 13, 2009 11:53 am ]
Post subject:
op, similar event here check this thread out http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=41315 Also the electric fan is close to useless when your at freeway speeds (imho) When your towing your experiencing an increased thermal load via the trans and a cooled egr, and a ton of btu from the intercooler. (aka your headwind, i assume you were holding a high gear and doing so with HIGH boost)

Author:	CRDMiller [ Mon Apr 13, 2009 12:02 pm ]
Post subject:
mitchell did you buy the crd from chula vista or the one from la mesa? I've been looking at crd's in this area for years and I've only seen four, 2 in the last four months.

Author:	mitchell [ Mon Apr 13, 2009 1:36 pm ]
Post subject:	I wasn't clear enough in original post.
Hello, And thank you for the assistance In my original post, I missed the important detail that it is the fan in front of the radiator that is not coming on. The one to the rear functions. Is the front fan an auxiliary; Is it an extra? BlackLIbertyCRD, I turned on the a/c as you suggested. The main fan was working, I never saw it go off, even though I was just idling from a cold start in the driveway. However, the fan in front of the radiator did not come on. CRDMiller, I flew up to a little town in Montana and drove it back. Once I decided that I wanted one, and knowing that they were not native to California because of the ban, I began searching elsewhere and eventually found it. The flight was not much. Of course, I did not get all of the negs from the salesman, even though I explained that I was at his mercy. Anyway, it had super low miles and, I thought that maybe the late mfg. date might include some resolutions with at least some of the problems that these vehicles develop. Mitchell

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Radiator Fan - Never Comes On? How Can I Test It? http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=42198	Page 1 of 1

Author:	CRDMiller [ Mon Apr 13, 2009 1:55 pm ]
Post subject:
Technically the front fan is normal (gassers have only this fan UNLESS you get the towing package witch adds the mechanical fan) Defiantly turn on the ac. The electric fan WILL come on. Check relays and fuses. There's a good thread on it somewhere and i will find it, and post. I bought mine in Texas and did similar. But there have been several sold in ca in the last few years.

Author:	BlackLibertyCRD [ Mon Apr 13, 2009 1:59 pm ]
Post subject:
mitchell, The fan in between the grill and radiator is an electric fan that you can see without raising the hood. I will check mine and get back to you when it works with the A/C on. It could also run through a high pressure switch to insure it won't come on unless needed.

Author:	CRDMiller [ Mon Apr 13, 2009 2:06 pm ]
Post subject:
TSB: Quote: NUMBER: 08-043-05 GROUP: Electrical DATE: August 11, 2005 THIS BULLETIN IS BEING PROVIDED IN ADVANCE. DO NOT PERFORM ANY ACTIONS RELATED TO THIS BULLETIN UNTIL AUGUST 26, 2005. THE DRB III SOFTWARE VERSION MUST BE AT LEVEL 62.2 TO PERFORM THIS BULLETIN. THE DRB III SOFTWARE WILL BE AVAILABLE ON TechCONNECT BY AUGUST 26, 2005. FOR MARKETS OUTSIDE OF THE UNITED STATES AND CANADA, THE DRB III VERSION 62.2 SOFTWARE WILL BE AVAILABLE ON CINONConnect AND TechCONNECT BY AUGUST 26, 2005. THE DRB III VERSION 62.2 SOFTWARE WILL ALSO BE AVAILABLE ON THE ITIS DVD SEPTEMBER 2005 RELEASE. SUBJECT: Engine Temperature Gauge - Indicator Reads A Higher Temperature Than Actual OVERVIEW: This bulletin involves reprogramming the instrument cluster control (CCN) module. MODELS: 2005 (KJ) Liberty / Cherokee NOTE: This bulletin applies to vehicles equipped with a 2.8L turbo diesel engine (sales code ENR). SYMPTOM/CONDITION: The customer may notice that the engine temperature gauge may indicate that the engine temperature is high. In hot ambient temperatures, and under certain driving conditions of extended uphill driving while towing a trailer, the engine temperature indicator may indicate slightly above the 3/4 normal operating temperature mark on the temperature gauge (but below the engine hot temperature markings). This condition may be caused by an incorrect calibration of the of the engine temperature gauge. New CCN module software corrects the old engine temperature gauge calibration. DIAGNOSIS: If the engine and the cooling system are operating correctly, and the above condition is present, then perform the Repair Procedure. SPECIAL TOOLS/EQUIPMENT REQUIRED: CH6000A Scan Tool (DRBIII®) NUMBER: 08-043-05 GROUP: Electrical DATE: August 11, 2005 CH7000A/7001A J1962 Cable with red DRBIII® connector REPAIR PROCEDURE: NOTE: Before proceeding verify that the DRBIII® software version is at level 62.2. 1. Connect the DRBIII® to the vehicle Data Link Connector (DLC) 2. Turn the ignition switch to the "ON" position. 3. Using the DRBIII® scan tool recalibrate the instrument temperature gauge. a. Select "DRBIII® Standalone" b. Select "1998 - 2006 Diagnostics" c. Select "All (Except Below)" d. Select "Body Interior" e. Select "Electro/Mech Cluster (MIC)" f. Select "Miscellaneous" g. Select "Recalibrate Temp Gauge" option. 4. If the recalibration of the instrument cluster was successful, the DRBIII® will display the following message: "Recalibration Successful". 5. If the version level of the original instrument cluster software allows recalibration, but the recalibration of the instrument cluster was NOT successful, then the DRBIII® will display one of the following messages: "Recalibration Failed" or "Write To Memory Address Failed". If one of these messages occurs repeat the above steps. 6. If the instrument cluster has already been recalibrated to the correct software version level, then the DRBIII® will display the following message: "Gauge Already Recalibrated - Press Any Key to Exit". 7. The DRBIII® will display the following message if the original instrument cluster software version level is not the correct version level for recalibration: "MIC Software Version Incorrect - Press Any Key to Exit". 8. Verify that the instrument cluster engine temperature gauge has been recalibrated by selecting the "Recalibrate Temp Gauge" option again. The DRBIII® should display the following message: "Gauge Already Recalibrated - Press Any Key to Exit". 9. Turn the vehicle ignition switch to the "OFF" position 10. Disconnect the DRBIII® from the vehicle DLC. POLICY: Reimbursable within the provisions of the warranty. TIME ALLOWANCE: Labor Operation No: Description Amount 08-45-10-94 Reprogram Instrument Cluster Control (CCN) Module - 2.8L Turbo Diesel Engine Only 0.2 Hrs. FAILURE CODE: AM Authorized Modification Warp2diesel from fsm Quote: ² Engine Temperature Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is within the normal operating range [up to about 124° C (255° F) for gasoline engines, or about 110° C (230° F) for diesel engines], the gauge needle is moved to the actual relative temperature position on the gauge scale. ² Engine Temperature High Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is high [above about 127° C (260° F) for gasoline engines, or 112° C (233° F) for diesel engines], the gauge needle is moved into the center of the red warning zone on the gauge scale. ² Engine Temperature Critical Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is critical [above about 132° C (269° F) for gasoline engines, or 115° C (239° F) for diesel engines], the gauge needle is moved to the high end of the red warning zone on the gauge scale. For the gasser, the spread between normal and hot is 5 degrees F and 14f for critical. Our diesels it is 3 degrees between normal and hot and 9 degrees normal and critical. The span is tighter. To test the following: 1) Temp sending unit measure the cylinder head next to the sending unit with engine warmed up and gauge reading normal and record. If the thermometer reads normal with the gauge at hot or critical, the sending unit, Body control Module or gauge is the problem. 2) Engine warmed up, measure the radiator top inlet and lower outlet and record the difference. If the two readings are very close when the gauge reads hot, the radiator is the problem. 3) Engine warmed up, measure the head temp near temp sensor and the engine outlet pipe where the upper radiator hose is attached and record. If the difference between cylinder head reading and the engine outlet pipe reading climbs when the gauge reads hot, the thermostat is not fully opening or there is a restriction in the cooling system. and some electric fan info via bill.barg quoting fsm Quote: From the service manual. E fan turns on when the PCM feel s like it. Many inputs including battery temperature !?!!? The electric radiator cooling fan is controlled by the Powertrain Control Module (PCM) through the radiator cooling fan relays. The PCM regulates fan operation based on input from the engine coolant temperature sensor, battery temperature sensor, air conditioning select switch and vehicle speed. The fan is not energized during engine cranking regardless of the electrical input from the temperature sensors and air conditioning switch. However, if engine operation conditions warrant fan engagement, the fan will run once engine starts. On vehicles NOT equipped with AC: The relay is energized when the coolant temperature is above 80° C (176° F), or battery temperature sensor above -12° C (10° F). It will then de-energize when coolant temperature drops below 82° C (180° F), or battery temperature sensor below -9° C (16° F). Vehicles Equipped with AC: In addition to using coolant temperature and battery temperature sensor to control cooling fan operation, the cooling fan will also be engaged when the air conditioning system is activated. The relay is also energized when air conditioning is selected and coolant temperature is above 95° C (203° F), or, air conditioning is selected and battery temperature sensor is above 41° C (106° F). It will then de-energize when air conditioning is selected and coolant temperature is below 92° C (198° F), or air conditioning is selected and battery temperature is below 38° C (100° F). MITCHELL 1 ARTICLE - 2006 ENGINE Cooling - Liberty Page 1 of 1 http:// hope this helps.

Author:	mitchell [ Mon Apr 13, 2009 3:38 pm ]
Post subject:	Fuse and Relays
Hello, Thanks for finding those posts with the bulletins. I see where it is noted that the electric fan should come on with the a/c turned on. However, is that only in conjuction with the other stated parameters respecting the other sensor readings? There seemed to be a number of combinations possible that I'm sure the little on-board computer can sort out (not necessarily the little one in my head). And, if those parameters must also be met, even with the a/c on, before the electric fan comes on, is it possible that this engine has just never gotten hot enough to meet the conditions to make it run? Or, am I misreading it and the e fan should come on whenever the a/c is turned on? Except for the one time climb of the needle during that towing into a head wind, there has not been any noteable overheating. Although, I have more than once thought I smelled a little radiator fluid. But there has never been any over flow or observed spillage. It was just the case that I have never seen this fan come on. (May be unrelated info.) Also, I have heard a little whining noise, kind of like a soft alarm sounding, at the front of the vehicle just after shutting it off. (I just remebered this) It lasts for about five to ten seconds plus the time it took to get out, close the door and walk around front. I am wondering if the extra mechanical fan behind the radiator might be keeping the engine cooled enough as to not provide the heat levels necessary to switch that electric fan on. On a different track, I looked in the Owner's manual and there appears to be a 40 amp fuse at F2 for the Radiator Fan and two Half ISO relays, one at R34 for Rad. Fan Hi and one at R40 for Rad Fan Lo located in the Power Distribution Center box under the hood. If these are testable as a first step, or even plausible as a cause, how would it be done? Mitchell

Author:	CRDMiller [ Mon Apr 13, 2009 4:06 pm ]
Post subject:
First, the sound you hear is 10000% the fcv and is normal. As far as testing the relay's i would swap the two (not sure you can) aka low and high, no way that both are faulty (right?!!) LOW is almost always going to be on if your ac is on. It is entirely possible that your electric fan does not work and only your mechanical fan has been in operation however you do not want this to happen because the electric fan is more efficient, significantly so. The goal here is to use the minimum amount of system power be it kinetic to electric via alt to kinetic again, aka the e fan, or kinetic via the mechanical fan to cooling. As far as testing the relays go, it can be done fairly easily by supplying a 12v source to the proper pins and using a multi meter to test continuity between the 12v source and the gate. You can look this info up on Google or just use the pin diagram on the relay itself. IF you are not familiar with electrical work i may be faster and easier for you to simply buy a relay from the dealer or whatever other source, napa, autozone, etc. Or use a realy that you know works. Like mine, for instance :P That would be a definitive and non skilled way to troubleshoot. (no offense intended, were not all mechanics) It in incredibly unlikely that your electric fan has both relays non operational but not a blown fuse. It's more likely that the fan itself has failed or is damage/disconnected. Again i would swap the relays if you can, turn on the veh, turn on the ac. You should hear the electric fan. (on low) If this yield negative results, i would (test the relay) use a relay you know works, check the fuse, check that the fan is connected.

Author:	CRDMiller [ Mon Apr 13, 2009 4:14 pm ]
Post subject:
I just checked, swap relay 33 with 40 (33 is blower motor for the ac/heater/vent, it's EASy to check that) And see if your blower motor works. There ya go. Hopefully it wont. Then you'll know it was just the rad low relay. Also i just started my crd and turned on the ac, it had been sitting for 2 days, the fan came on immediately, it is 78f out here right now.

Author:	mitchell [ Mon Apr 13, 2009 6:15 pm ]
Post subject:	same
CRDMiller, I switched the 40 amp fuses from blower and rad fan and the blower fan still ran. The radiator fan still did not with the a/c on. Plus the see through top on the fuse allowed me to see that the fuse link still appeared undamaged. I could not easily get the relays out. I did not want to pry without knowing how much pressure is appropriate before breaking. And, how much a replacement is. Allow me to ask you, have you had your CRD to any of the dealerships down here, and if so, have you found one that you are satisfied with? This because, so far, I have not had a good experience with two dealership service departments already. The first was on the way home with the Liberty after purchase. It was due for the 12,500 and I did not want to wait nor trust whatever work the selling Honda dealership had done prior. I took it to a Dodge dealership in Las Vegas, Desert something. Then, I went to Carlsbad a couple of times and I won't go over the details right now. Mitchell

Author:	CRDMiller [ Mon Apr 13, 2009 6:38 pm ]
Post subject:
This should be a relatively easy thing to repair, that said, not the fuses, the RELAYS. The likely points of falure are relay, wire, fuse, fan. As far as positive experiences at the dealerships, no. I've been to poway, and also to carl burger (witch has better reviews than poway) and i was not pleased with either. They were both clueless. Carl burger was so bad that the service writer made comments like "we don't support these and your warranty is no good here" I had to bicker with them about warranty coverage, not a good first step. "California does not have these we don't work on them"

Author:	mitchell [ Tue Apr 14, 2009 2:09 pm ]
Post subject:	Same
CRDMiller, I will try again to get the relay out and switch it to see if it is that. I have found some hits on google search that suggest for earlier year models there is also an in line fuse behind the passenger headlight that can not be gotten to without pulling the bumper cover off. I could find nothing for 05 06, so it is uncertain to me whether that in line fuse is still utilized for my model year. [My dealership experience includes two trips for a brake pedal sensor that needed only adjusting, but was replaced twice before adjusting. A glow plug module replaced because I was looking for the wrong dash lamp and the weather was too warm. The light still did not come on at ignition until the weather cooled down. And, body damage to the paint on two consecutive trips which was bad enough to get my insurance to pay for. Exactly, they knew they did it, but refused to pay. Unfortunately, since the service manager and writer ended up lying to the owner, I now can not trust them at all (sour grapes on their part). It seems they want to replace as many parts as they can under warranty rather than deny. They then get payed by the corporate if I understand correctly. Of course, they can not b.s. the factory as to additional parts necessary, so in the end, they probably could do better by denying warranty service and charging the customer for work they don't have to verify as necessary. I'll try another dealership for my battery replacement under warranty and if I haven't solved the problem, maybe ask them to energize the fan to see if it will come on (I think they can do that) and post the satisfaction level] My appologies for all of the off topic commenting. Mitchell

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Author:	vtdog [ Tue Apr 14, 2009 9:23 pm ]
Post subject:
I just want to add that it has been my experience that the secondary fan comes on very rarely only in the summer when the engine has been run a long time, or in heavy traffic. If I hear it running when I stop I let the Jeep idle for a few minutes and it turns off. I don't know the temp which trips the relay, but my gauge does not go above midpoint and sometimes it comes on and sometimes it doesnt seemingly at the same temp on the gauge. So, I suspect your fan might be fine, but is just waiting for the hot weather.

Author:	hatchetman [ Wed Apr 15, 2009 4:31 pm ]
Post subject:
Mine has been on only once that I can recall. It was coming back from Port St. Lucie, FL, at the end of june and it was 95 degrees plus. I let it idle at rest stops and the aux fan was on when I came out of the restroom each time.