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Old 09-02-2007, 08:58 PM   #1
MISSV23
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Where Is The Radiator Fan Relay Swich Located

PLEASE HELP ME I NEED TO KNOW WHERE IS THE RADIATOR FAN RELAY SWICH LOCATED ON A 2000 JEEP GRAND CHEROKEE LAREDO. MY CHECK GAGES LIGHT COMES ON AND THE TEMP GAGE IS ON 260 I HAD IT CHECKED OUT AND MY RADIATOR COOLING FAN ISNT RUNNING.
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Old 09-02-2007, 11:06 PM   #2
Bob D.
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Re: Where Is The Radiator Fan Relay Swich Located On A 2000 Jeep Grand Cherokee Laredo

It's under the passenger side headlight.
Click here for details.

http://rigs.corequipment.com/cebby_W...ling.htm#relay

Before starting any work on the relay I would make certain it isn't a bad electric fan.
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Old 10-16-2007, 06:08 PM   #3
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Thumbs up Re: Where Is The Radiator Fan Relay Swich Located On A 2000 Jeep Grand Cherokee Lared

Thanks Bob D! I just had my JGC checked out today, found out the fan ctrl relay was bad. I would have been chgd $300+ to have it done. By using your info I did it in less than 1/2 hr and saved apx $250.

You are truly a God-send!

Thanks again!
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Old 06-11-2009, 08:57 AM   #4
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Re: Where Is The Radiator Fan Relay Swich Located On A 2000 Jeep Grand Cherokee Lared

Not having any exact directions on where to cut the radiator support, I ended up with 2 holes in it....so here is what I learned from the experience. Once you remove the right side headlight, on the black horizontal plastic support is a molded in water runoff trough that goes from the 'vertical wall' behind the headlight to down under the headlight and under the front bumber. Start your hole about 2 inches away from the vertical wall and center your cut on the trough. The width of your cut should be about 5 inches left to right, again centered on the trough. The hole size, front to back should be about 4 inches to give you clearence to get your socket in there and be able to pull the old relay out. Once you replace it, it is very difficult to epoxy the piece back in, so I had a piece of the roofing material that has a tar adhesive with a thin tin backing on it. (They use it to stop ice backup on the edge of roofs). Just throw away the cut out piece and put down this roofing material. All you want to do is stop water from getting underneath the headlight and getting to the relay. I have a picture of my cutout but don't know where to post it on the net so everyone can see it. I bought my relay from a parts store for $35. Watch out for relays from junk yards!! Hope this helps someone. Skip in MI 6-11-2009
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Old 06-11-2009, 09:33 AM   #5
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Re: Where Is The Radiator Fan Relay Swich Located On A 2000 Jeep Grand Cherokee Lared

Those aftermarket relays have not been reliable in many reports. Don't immediately rule out the relay because it's new if you find you're having cooling issues/fan problems again.
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Old 06-23-2009, 02:29 PM   #6
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Re: Where Is The Radiator Fan Relay Swich Located On A 2000 Jeep Grand Cherokee Lared

I just replaced mine last night also in about 10-15 minutes. I found it was simple enough to just drill two 1/2" holes about 2" apart above the screws holding the relay. You can touch the relay by reaching through the large hole in the back of the housing so determining where to drill isn't hard. If you miss a little you can egg the holes easily with the drill.

Once the holes were drilled, I used a socket + extension to reach the screws. I reached in from the back and grabbed the upper screw as I removed it. Since I could not reach the lower one, I put a blob of grease into the socket so the screw stuck to it as I pulled it out.

Once the screws were out I fished the relay up through the large hole in the back. To release the connector, pull the red tab back a bit then press on the black release tab back near where the wires attach while gently pulling the relay out.

Reassembly was just the reverse including the grease in the socket.

I didn't bother plugging the holes because that whole area hardly seems waterproof anyway and I doubt a little water would hurt much. Plus the holes I drilled weren't into the gutter part of the plastic. If water is a concern it would be simple enough to dab some sealer in to block 1/2" holes. The other reason I didn't bother is now it's a 5 minute job and $35 part even if it fails again.

One pitfall I ran into: The headlight assembly is held in by the long screw plus 2 press in posts. The lower inside post would not go back into place so when I checked I realized the yellow plastic insert had come out of the housing and was stuck on the post on the back of the headlight. I pulled it off and put it back into the housing and all was well. I notice the guy in the link posted above appears to have the post broken off the headlight and stuck in that same insert so obviously someone forced that one a bit.
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Old 06-25-2009, 01:46 PM   #7
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Re: Where Is The Radiator Fan Relay Swich Located On A 2000 Jeep Grand Cherokee Lared

Stickied, since this is a recurring issue and good info and the solution is here.
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Old 06-29-2009, 09:27 AM   #8
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Re: Where Is The Radiator Fan Relay Swich Located

I have replaced mine at least 4 times and the radiator fan twice. {over a span of 260,000km/160,000mi} Just blew another one on weekend. In the past the Dealer could not locate problem and it appears there is no solution. One thing that one mechanic told me is that a heat conductive compound should placed between the relay and its mounting location. Apparently these solid state relays switch a heavy load {I think it's around 30 to 40 amps} and that the relay gets quite hot. I asked why the fan runs even when I am going to the highway at highway speeds {-25 outside} and heard from some tech in a Chrysler forum that the computer cycles the fan as well as monitor rad temperature. I think there is a design flaw but no one has yet to offer the real reason these fan relays fail.

Just my comment.
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Old 06-29-2009, 11:07 AM   #9
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Re: Where Is The Radiator Fan Relay Swich Located

99grncherokee,

It sounds like you have some other problem there contributing to all those failures. Your fan shouldn't run much at highway speeds and I suspect that's why you're putting way more hours on the relay than normal. Do you have A/C and if so does it work fine? The reason I ask is the fan runs with the A/C but if the A/C is low on coolant it will cycle on and off repeatedly. The peak current is higher when starting/stopping a motor and that would be hard on the relay. I had a Neon with that problem that burned up its mechanical relay. I would also make sure (using OBDII) that your coolant temp isn't sensed as hotter than it really is. I don't know the specs for when the fan starts & stops but others could at least compare theirs.
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Old 06-30-2009, 10:12 AM   #10
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Re: Where Is The Radiator Fan Relay Swich Located

Thanks for the info 35charlie

Ok replaced the relay, picked one up from chrysler dealer. The relay came with large rivets and what appeared to be large 1/4" heavy duty self tapping bolts with detailed instructions. Depending on the manufacturing date of the vehicle would determine whether or not to use rivets or bolts. The instructions also indicated the relay may be behind the "left side" headlight on years after 99, assuming left side is driver side although not sure, this might be a typo? Don't know about that as mine is behind passanger side. The point that I am trying to make here is the instructions were adamant about having the relay properly seated against the metal so that it acts as the heat sink. Judging by the fasteners provided I can see they are not fooling around. My relay had been changed several times and the one I just replaced had only small sheet metal screws holding it down, one of which was stripped. Needless to say I believe this to be the cause of failure. So if you have to change the fan relay, consider the heat path from the aluminum backing on the relay to the steel inner fender, the better the contact the longer the relay will last.

Dave
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Old 06-30-2009, 10:31 AM   #11
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Re: Where Is The Radiator Fan Relay Swich Located

Further to your comments 35charlie,

Yes I do have ac and it does work fine. I think that is an excellent idea about the coolant temperature perhaps out of calibration on the sensor and the computer would keep cycling the rad fan. I did take to chrysler about a year ago and fully explained my situation as to why all the relay failures, having to change the relay for the fourth time as well as their recommnedation to change the rad fan assembly AGAIN. The dealer said they will look into and diagnose. Their comments," the rad fan motor was drawing to much current that is why the relay went and could not offer any other explanation" so I paid for the jeeps "third" fan assembly and fourth fan relay even though the root of the problem had not been addressed. I still think its something to do with the computer programmed to cycle the fan even though the temperature is normal. I know the fan runs when I am on the highway because my headlights will dim for brief moment as the fan starts up, and no I do not have the defrost on. Next time i see someone with a code reader I will get them to check but you would think the dealer would have looked into that.

Dave
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Old 07-06-2009, 09:18 AM   #12
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Re: Where Is The Radiator Fan Relay Swich Located

I just replaced the relay this past weekend. I remounted the relay to a better spot to replace if the need pops up. I was told that the relay is a bad design and it was changed for the 2002 series. The dealer said it would replace the module for a bosh relay. Just as I was taking the car in the dealership closed. Has any one heard or done this before? If so can you share the detail, I would like to get rid of the module all togeter with.
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Old 07-06-2009, 09:29 AM   #13
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Re: Where Is The Radiator Fan Relay Swich Located

The relay is solid state and requires a signal from the computer to turn on, don't know if this is a specific pulse or what the voltage is. I would be cautious about another brand of relay unless you know it is actually compatible and has worked on others. Again, if you do go with factory, insure the relay is heat sinked properly.
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Old 03-05-2010, 10:46 AM   #14
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Re: Where Is The Radiator Fan Relay Swich Located

I have a 99 Grand Cherokee...if the fan continues to run until I disconnect my battery would that mean my fan relay is bad or my coolant sensor is bad?
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Old 03-05-2010, 11:26 AM   #15
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Re: Where Is The Radiator Fan Relay Swich Located

Quote:
Originally Posted by clay.jones View Post
I have a 99 Grand Cherokee...if the fan continues to run until I disconnect my battery would that mean my fan relay is bad or my coolant sensor is bad?
When my fan relay failed it first stuck on until I pulled the fuse. Then it would no longer start. I don't know what a coolant sensor costs but I would go with the least expensive one first. I take that back. Considering the track record of fan relays I would just replace it.
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