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.:banghead:

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

http://rigs.corequipment.com/cebby_WJsite/cooling.htm#relay

Before starting any work on the relay I would make certain it isn't a bad electric fan.

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!

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

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.

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.

Stickied, since this is a recurring issue and good info and the solution is here.

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.

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.

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

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

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.

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.

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?

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.

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?

Fan Relay. Your coolant sensor gets turned off when the vehicle goes off.

OK so the coolant sensor was cheaper but I replaced the fan relay and now all is well...well except for my thermostat is now sticking...blaaah but I love my jeep so I guess I'll just replace it and keep on going

for any one with a 2001 jeep grand cherokee looking for a fan relay location other than in your normal under hood compartment.all the threads about takin front bumper off and takin out battery and all this other stuff is wrong.this is all you need to do popout your passenger headlight look to your left you will see plastic covering there ar no wires in the way cut a 2 to 3 in square an you will see the fan relay unbolt from frame get new one replace an that is it.takes 15 to 20 mins to do o there is one screw to take off an that is the one holding headlight nothing more to take off leave other things alone you make to much work doin everything else.

its in a weird spot....I was told to take the passengerside headlight out and cut a section away in the bottom and it should be right there. That is supposed to be the easiest way other than taking the front bumper off...hopefully someone can verify this to be sure so don't attempt until someone else says this is correct. Good luck

02 Jeep GC. fan stayed on last nite after shut down, had to jump this morning, fan still running. dealer said relay switch needs replaced. On way to get, fan stopped, started overheating. cooled down, got to family garage and went to get new relay. Installed and still no fan running. We are stumped. checked plug ins and fan itself, still nothing. Help!

Blaze, Welcome to AF. It's usually best to start a new thread...but since you've posted here:

The fan doesn't run until either the vehicle reaches a certain temperature, or in some cases when the AC is turned on.

I'd suggest starting it and letting it run for about 20 minutes, keeping an eye on the temperature gauge and watching for the fan to come on.

Yes this is the way how to change the relay fan in jeep. easy and fast just drill a small about 2" diameter hole to have easy access to the relay good job

I drive a 1999 Jeep Grand Cherokee 4WD. The radiator fan continue to run when I parked it at work, later that night the battery was dead, I jumped started it and drove home. The Relay shorted out-no big deal, I found out the relay is located below the passenger side headlamps. Remove the one screw holding the headlamp in place, pull out the whole headlamp assembly. The plastic fascia was already cut, so I think it was repaired when it left the factory. I the original owner. Cut the plastic to get easy access to the relay. Release the red locking tab, pull out the socket, remove and replace the relay.
Later, years later, the fan stopped working again, so I thought it must be the relay. Nope, after 11 years the radiator fan motor stopped, must be all the carbon dust build up. Use a continuity meter to check the motor, then run voltage to the motor and see if it runs, mine didn't until I helped it start spinning. Becareful not to get caught in the engine belt. Removing the radiator shroud is a little bit tricky. I had to remove the radiator hose and pulled the shoud straight up. Remove the bolts holding the shroud in place and disconnect the motor connection plug. Remove the locking ring for the fan blades, disassemble the fan motor from the shroud, try knocking the motor assembly and see how much carbon comes out. You can try blowing the carbon out while you turn the motor shaft. I saved some money by cleaning the motor out. I'll have to buy a new motor if it goes out again.
1. fan relay bad.
2. blew fuse in power distribution
3. control for relay is from powertrain control module
4. B+ side of the relay is hot to ground.
5. Output side will be hot to ground when the relay is switched on. A/C running or engine at temperature.

Took me a while to get it all figured out. Hope this helps anybody with the same problem.

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

http://rigs.corequipment.com/cebby_WJsite/cooling.htm#relay

Before starting any work on the relay I would make certain it isn't a bad electric fan.
I am so thankful for this post and the link that was with it. I did not have the right tool to cut the plastic, so still had to take car to shop. However, I gave them permission to cut a hole in the plastic part (instead of removing front of car) and saved $100+ dollars on the servicing of this item. Not perfect, and not cheap, but better than a full price dew job. Thanks again.

I also own a 2000 jeep grand cherokee and am about to replace my fan relay switch for the 3rd time...what i found out today is the contacts on the connector plug can burn off and they make a replacement connector for this... i'm guessing there is a cycle flaw of sorts from the computer to relay as my waterpump and thermostat and fan have all been replaced... this seems to be a real common problem...i'm going today to buy new connector and relay switch and see if it fixes it totally... will post how i make out.

I have a 05 grand prix and my radiator fans don't come on when I start my car. Is that normal or what...I started my car at one point n I hit the gas then the fans came on..are they suppose to do that ?someone please get back with me on this...thanks

A few years ago my temperature gauge maxed out into the red on my 2001 Jeep Grand Cherokee. I immediately pulled into a Goodyear service center. I paid them $75 to diagnose the problem and was told that my radiator fan motor wasn't working.

I received an estimate of over $1,200.00 because they told me that I had to buy a whole new radiator fan unit because you couldn't buy just the motor. And I was told that to replace it would entail taking off the bumper, removing the front end of the car, etc. Which was why it was soooo expensive to fix.

I didn't have that much money so I drove home (turning off engine at every stop) and did some testing myself. I ran a wire directly from positive terminal of my batter to the fan motor's positive lead and guess what? The fan worked. The experts that charged me $75.00 to diagnose the problem were wrong.

So I installed a switch between my battery and the fan's motor and when I drove the Jeep I would just switch the fan on. Not the best solution, but it worked until I could solve the real problem.

I also pulled out my repair manual for my Jeep and found that the fan's housing unit can be pulled straight out by removing just a couple of bolts.

I went back to Goodyear and got my $75 back.

After some research and eliminating various causes I found out that the problem was probably the fan relay. I didn't want to cut through the plastic behind the headlight if I could help it so I found a local mechanic that replaced the relay for $50 plus parts (around $50 more).

I told him that I had read you could cut through the plastic and I didn't want that done. He told me that he could reach behind the housing (because he had small hands) and didn't have to remove the bumper. He said it was still a big chore, and I thought $50 was a bargain. Especially compared to the $1,200.00 estimate I had received earlier.

I used him 3 more times over the next 3 years because the relay was going out about once a year.

Then yesterday it happened again so I decided to bite the bullet and cut through the plastic and replace it myself. I brought out my Dremel tool and pulled out the passenger headlight and guess what? There was big hole already cut exposing the fan's relay. The mechanic that had been doing what I thought was an amazing job had lied to me about the way he was replacing the relay.

So now I can easily replace it myself AND I'm going to save my receipt because the fan relay has a lifetime warranty. Now instead of paying $100 a year, I can do it myself in 5 minutes for free.

Changed mine this weekend Thanks for the tips and pics They made my job much easier