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Unread 07-18-2014, 07:31 PM   #1
jenniferny
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1998 5.9 Limited Cooling Fan

Dumb question time. My fan motor finally went bad and I am ready to do the upgrade with the PM9069 motor & WPT168 Plug, but I have a question. I am trying to unplug the factory fan motor from the wiring harness plug, but they do not want to come apart. There is not much room, so I can not see very well. What is the key to getting the plug to come apart? There must be some type of release to press or pull on, but I can not see what it is, and I do not want to damage the plug or the wiring. I tried pulling the red tab out and it did not seem to help. Any help or advice would be greatly appreciated!!!!

I upgraded the Cooling Fan Switches to a 190 degree switch in the upper hose and a 180 degree switch in the lower hose only to discover that the low speed fan motor did not work at all, and the high speed ran slow and sounded like it was on its last leg. I bought the motor and the plug and went to do the install tonight, but I can not get the plug to seperate.


cooling-fan-motor-plug-01.jpg   cooling-fan-motor-plug-02.jpg   cooling-fan-motor-plug-03.jpg   cooling-fan-motor-plug-04.jpg   180-degree-lower-hose-switch-02.jpg  

190-degree-upper-hose-switch-01.jpg  
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Unread 07-18-2014, 07:48 PM   #2
jeepjeepster
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In your second picture there is a tab on the left. Push it down and pull apart. It normally had a red slider to lock it.

What kinda switches did you buy? Brand and such.
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Unread 07-19-2014, 12:50 PM   #3
jenniferny
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Quote:
Originally Posted by jeepjeepster View Post
In your second picture there is a tab on the left. Push it down and pull apart. It normally had a red slider to lock it.

What kinda switches did you buy? Brand and such.
Jeepster, Thank You Very Much!!!!!

I found the tab and pushed down, but it was still very difficult to pull the two pieces apart, I guess I am just not as strong as all you guys, but I was able to get them apart.


One more question... The Fan Shroud on the 5.9, is that just held in on by the two bolts/nuts on the top or is there something to unbolt or disconnect on the bottom of the shroud too?


Thanks Again!!
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Unread 07-19-2014, 06:42 PM   #4
KJK
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Quote:
Originally Posted by jenniferny
The Fan Shroud on the 5.9, is that just held in on by the two bolts/nuts on the top or is there something to unbolt or disconnect on the bottom of the shroud too? Thanks Again!!
It's just the 2 nuts at the top and then it can be wriggled free. There are some tabs that locate it on the bottom to hold it next to the radiator so be sure these are engaged when you reinstall it.
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Unread 07-19-2014, 09:00 PM   #5
jenniferny
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Quote:
Originally Posted by KJK View Post
It's just the 2 nuts at the top and then it can be wriggled free. There are some tabs that locate it on the bottom to hold it next to the radiator so be sure these are engaged when you reinstall it.

Thank You!! The Factory Service Manual was not very clear at all on how the shroud was held in place, it mentioned removing the cooling fan module bolts, but that was all it said and I wanted to make sure before I tried to remove it and found that there was more than I could see.

Many of the things that I do to my Jeep are things that I have never done before, and working on a 98 5.9 Limited is WAY different than working on a 79 Trans Am.

Thanks Again for your help!!
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Unread 07-21-2014, 03:27 PM   #6
RWC
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Quote:
Originally Posted by jenniferny View Post
I upgraded the Cooling Fan Switches to a 190 degree switch in the upper hose and a 180 degree switch in the lower hose only to discover that the low speed fan motor did not work at all, and the high speed ran slow and sounded like it was on its last leg.
The switches you acquired are also part of your problem. The radiator will drop the temperature about 10 degrees as it flows from the upper hose to the lower hose. If you run a 180 degree switch in the lower hose, it's going to turn on when it sees 180 degrees, which means your upper switch will be at 190. So the high-speed fan will always activate at the same time as the low-speed fan, and the ignition relay (don't ask my why it's called that) will override your low-speed fan in favor of the high-speed.

My question for you is this: when do these switches turn off?
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Unread 07-21-2014, 06:22 PM   #7
jenniferny
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My coolant switch temperature choices

Quote:
Originally Posted by RWC View Post
The switches you acquired are also part of your problem. The radiator will drop the temperature about 10 degrees as it flows from the upper hose to the lower hose. If you run a 180 degree switch in the lower hose, it's going to turn on when it sees 180 degrees, which means your upper switch will be at 190. So the high-speed fan will always activate at the same time as the low-speed fan, and the ignition relay (don't ask my why it's called that) will override your low-speed fan in favor of the high-speed.

My question for you is this: when do these switches turn off?

According to Mopar Parts:
the Upper Hose Switch closes at 210 degrees
The Lower Hose Closes at 190 degrees

In the diagram below it lists temperatures
for the low speed ON to be: 214-219
for the high speed ON to be: 220+

I believe those temperatures are for engine temperatures at the coolant temperature sensor in the intake manifold and not the temperatures at the switches. If I am wrong please correct me.

According to Mopar Parts:
the upper hose switch closes at 210 degrees
the lower hose switch closes at 190 degrees

56022390AA
SENSOR, Lower Coolant Temperature
Middle East Equipment Group(NMX), Lower Hose, Severe Duty Engine Coolant (NMS) 190,

56022391AA
SENSOR, Upper. Coolant Temperature
Upper Hose, Severe Duty Engine Coolant(NMS) 210

When looking up the coolant switches, the wording is very confusing, but knowing that the upper hose in the engine outlet, radiator inlet hose which means a higher temperature, and the lower hose is the radiator outlet, engine inlet which means a lower temperature makes it obvious that the upper hose switch must be the higher temperature switch. Please note the mention of lower AND upper hoses in the part description. Here is what I mean:
Inlet Hose, Middle East Equipment Group [NMX] Lower Hose, Severe Duty Engine Coolant [NMS] Upper Hose, Upper, 190F.

The temperatures that I chose for my switches are:
the upper hose switch closes at 190 degrees, 20 degrees lower than the factory switch, and opens at 175 degrees
the lower hose switch closes at 180 degrees, 10 degrees lower than the factory switch, and opens at 165 degrees.

My choices are close, but slightly lower than the factory switches. The purpose is to turn the fan on slightly earlier so the engine starts cooling a little sooner to prevent the temperature from getting up to high on hot days or especially on hot days when the A/C is on.

I knew going in that I may need to make changes, based on real world experience, but since BOTH the UPPER HOSE SWITCH AND the LOWER HOSE SWITCH are bad I knew I had to do something!!! I may also need to use a 190 degree switch in the lower hose, but I wanted to monitor the cooling fan going on and off for a while before changing to the 190 degree switch in the lower hose too. To monitor the fan turning ON/OFF I have two LED's that I am going to install in the dash that are wired to each switch to turn the LED ON when the switch closes, and OFF when the switch opens, just to make sure that the fan is not running all the time once the engine reaches operating temperature. If necessary, I have found a 195 degree switch to try in the upper hose if the fan does not turn off, this is 15 degrees colder than the factory switch instead of 20 degrees. If I need to go to 200 degrees in the upper hose, I will need to buy a different hose spacer with the correct threads to use a higher temperature switch, but they are available.

If my thinking is not correct, please show me where so I can review it.

Thank You!
98-5.9-cooling-fan-off-specs.jpg

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Unread 07-21-2014, 10:44 PM   #8
jenniferny
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5.9 Limited, Cooling Fan and Cooling Fan Motor Are Stuck Together

Another dumb question!!!

What is the key to getting the fan blade to release from the fan motor? I have sprayed it with PB Blaster and hit the motor shaft with a hammer with all of the bolts out of the motor so the weight of the motor would help them release from each other and the blade and motor are still stuck together. Is there something that I am missing?? I do not want to damage the fan blade, because they are so hard to find and when you do, expensive.

After I get them separated, is there a trick to get the fan blade to seat all the way on the NEW fan motor? If they are this hard to separate, I do not want to damage them when I am trying to put them back together???

When I read all of the threads on doing this, not once did anyone mention that they were hard to separate. Must be because I am an amateur!!!!!

From the looks of the radiator, it might very well be my next project! Does anyone make a three row radiator for the ZJ to give the cooling system more capacity??
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Unread 07-21-2014, 10:57 PM   #9
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There should be a clip holding the blades to the shaft.
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Unread 07-21-2014, 11:43 PM   #10
jenniferny
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Cooling Fan Blade Stuck on the Cooling Fan Motor Shaft

Quote:
Originally Posted by kg6mov View Post
There should be a clip holding the blades to the shaft.
kg6mov, thank you for the reply!!!! I should have posted photos with my first query so that you could see where I was at, Sorry!!

I did see the clip. Removing the clip was the first thing that I did. I wanted to get everything made of steel wire brushed, sprayed with rust converter and painted. Living in the rust belt you learn that this is a part of every job!!! Then I sprayed the cooling fan motor shaft with PB Blaster several times to disolve any rust that was there. That was over six hours ago, and the blade is still stuck on the motor. Thinking that with the weight of the motor to help me, I would tap the shaft with a hammer and they would fall apart. WRONG!! I have hit the shaft a number of times and it does not want to budge. Before I went any further or before I did any damage I wanted to ask the experts on the subject of ZJ Jeeps to see if I was missing anything.

Looking at the new motor, it looks like there is nothing else holding the blade to the motor.

Could it be just 16 years of rust and corrosion holding them together??????


.
cooling-fan-retaining-clip-removed-01a.jpg   cooling-fan-retaining-clip-removed-02a.jpg  
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Unread 07-22-2014, 02:16 AM   #11
Timo_90xj
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It's a tight fit. Wait until you get to install the fan blade to the NEW motor


What I did was spray the area with penetrating oil, then CAREFULLY start tapping the motor axle with a hammer/ mallet. You don't want to brake the fan blade assembly, so be gentle. It will start to pop off slowly but steadily. IIRC I had two 1/4" or 1/2" thick metal strips between the blade and the motor (whatever fits there) to support the blade from close to the fan motor axle.

I did this thing last autumn/ winter when my motor failed, and the hardest part of all was removing and re-installing the fan blade assembly
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Unread 07-22-2014, 09:54 AM   #12
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Definitely post pics and all p/n, etc for what you did to replace the fan...this is a good thread and I know someday I will have to deal with this...I fear the fan going out while out on a trip somewhere so I might just get all the stuff and do it pro-actively.
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Unread 07-22-2014, 11:26 AM   #13
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You need the fan motor and pigtail harness mentioned in the first post, remove the fan blade, remove current motor, replace with new motor, press in old fan blade, cut off OEM connector on the e-fan wire harness, splice in pigtail harness to factory wire harness.

If all goes well, it's done in couple of hours.
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1990 XJ Limited (4-door), 4.0 I6, AW4, NP242, ***rolled and totalled @ 165k miles***

***Under construction***
1990 XJ (4-door), 4.0 I6, AW4, NP242, PBR 42" tires, Unimog 404 portal axles, 110" WB, full cage + uniframe completely rebuilt, front 3-link + panhard / double triangulated 4-link rear,... ***SOLD***
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Unread 07-22-2014, 11:36 AM   #14
jenniferny
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Quote:
Originally Posted by Timo_90xj View Post
It's a tight fit. Wait until you get to install the fan blade to the NEW motor


What I did was spray the area with penetrating oil, then CAREFULLY start tapping the motor axle with a hammer/ mallet. You don't want to brake the fan blade assembly, so be gentle. It will start to pop off slowly but steadily. IIRC I had two 1/4" or 1/2" thick metal strips between the blade and the motor (whatever fits there) to support the blade from close to the fan motor axle.

I did this thing last autumn/ winter when my motor failed, and the hardest part of all was removing and re-installing the fan blade assembly
Thanks for the reply Timo.

How did you get the fan blade to seat all the way on the new motor? Did you bolt the motor in to the shroud and put a socket over the motor shaft so you would NOT damage the motor shaft and tap in on, or did you do it another way? How hard did you have to hit the fan to get it to go on?? Did you have to clean up the inside of the fan blade where the shaft goes with sand paper because of rust or corrosion? I have not gotten the fan blade off yet, so I have no idea what it will look like, where the motor shaft goes, when I do. I DEFINITELY DO NOT WANT TO DAMAGE MY FAN BLADE!!!!!!

The hammer that I am using is a Snap On BPD-12a, Ball Peen Dead Blow 12 oz hammer. Do you thing this is enough? I am afraid to go to big for fear that I may damage something a whole lot easier.

I just gave it another 30 or so whacks with the hammer after it sat all night soaking with PB Blaster. It has not moved even a half of a millimeter!

The reason for the motor replacement is that after I replaced both of the failed coolant switches I discovered that the low speed side of the fan was not working at all, and the high speed side of the fan ran slow and made a lot of noise. When I started I thought I was just going to be replacing the coolant temperature switches that I hoped would work instead of the factory switches that are not available anywhere.
dead-blow-hammer-01a.jpg  
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Unread 07-22-2014, 11:39 AM   #15
jenniferny
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Quote:
Originally Posted by Timo_90xj View Post
You need the fan motor and pigtail harness mentioned in the first post, remove the fan blade, remove current motor, replace with new motor, press in old fan blade, cut off OEM connector on the e-fan wire harness, splice in pigtail harness to factory wire harness.

If all goes well, it's done in couple of hours.
Again, thanks for the reply.

What did you use, or how did you press the blade on the new motor??
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