scorpion501

My daughters 2004 Grand Cherokee has been over heating randomly when idling. The temperature sending unit and thermostat have been replaced. Still no solution. I read on CF about others with similar problems. I also read on here about the fan control relay possibly being bad and started into that task. Removed the headlight, cut the hole and walla!! NOTHING!! The holes are there where the controller should mount but nothing is in the area. (see photo) I have looked around under and over the whole area and can't find it. It is not another style located in the fuse compartment under the hood. Is there another area where I can look? Any help would be appreciated. Ron

freegdr

sure it did'nt come loose and slide down ?

Kerns Menard

Where you able to locate the fan control relay. I have the same situation on a 2004 grand cherokee 4.0 liter. Please advise. Thank you

scorpion501

It took some time but I finally found the solution. I was barking up the wrong tree. It turned out to be low coolant. This particular engine has an unusual way of getting the cooling system filled. On the drivers side of the engine, just aft of the upper radiator hose connection on the top of the engine, there is an allen plug that needs to be removed and the engine finished filling with coolant. After the engine has cooled off I remove the radiator cap before removing the plug. (keeps it from spewing hot fluid all over). Leave the radiator cap off while filling the hole with coolant so you can see when the system is full. There must be a very slow leak in the system somewhere because I need to do this about every six months or so. Whenever the engine temperature gauge starts going high, I fill the system. You will need an allen wrench and a small funnel to fill the system. Hope this helps you out.

dave1123

My 2000 doesn't have that plug, but I take the temperature sensor out and fill the radiator until coolant flows out that hole, re-install the sensor, then top off the radiator. Your engine should keep itself full from the reservoir. You just add coolant to the reservoir when it gets low. My 4.0 even tells me when it's low in the overhead VIC. As far as the fan relay is concerned, they changed it to 2 relays in the PDC. I believe you'll find that info on wjjeeps.com

CrisostamoSH90

A side note about the relay, when I replaced mine a few months back it came with instructions to relocate the relay to the drivers side. I believe actually behind the headlight for better cooling than tucked in the bumper. Check there and see if you can find it. I wish I didn't just throw that in the trash! Also If you buy a Mopar relay they provide rivets for the new installation. Providing the best contact with the sheet metal it's mounted to optimizing heat dissipation

Hope that helps,
Nick

bigbadon

The fan relays (there are 2) are not behind the headlight. They are in the fuse box beside battery and very easy to get to.

dave1123

You see? I TOLD you they changed the circuitry! Don't mind me, I'm just a grumpy old man!

Gary Somers

I chose not to cut the hole and took the whole front end off to find NO RELAY as you have pictured.
Turns out the two relays for the fan is located in the fuse box behind the battery!
$10 part (each) and easy fix.

Gary Somers

Trying to locate the 2 speed relays for my 04 Laredo without success, I decided to check to see if the fan worked by jumping the connection at the plug and the fan kicked on. Going back to test the relays I decided to flip the AC on again because the fan worked for a short period yesterday. Sure enough the fan kicked on again.
Trying to figure out the connection, I could only conclude that the AC drew amperage and may fused a bad connection within the fuse panel.
I tightened all connections to the battery lead and started the motor. At 210 the fan kicked on!!!
3 more trial starts and letting the motor run for 5 minutes the fan stayed on as it should.
Hope anyone with similar issues can be helped with this.

dave1123

My God, Man! Take an airhose to that PDC and put the cover on it! Otherwise, later on, you'll be fighting corrosion and loose connections the likes of which you never seen! Oh, wait....I see the cover, but it looks quite dirty just the same.

Incidentally, a good thing to do with the relay under the headlight is bed it with the same compound they use under computer chips for good heat dissipation. It gets really hot from rapid cycling during low speed operation and it's carrying 30 amps. Great engineering using a 2-wire fan and a pulse modulated relay! Idiots! Your 2004 uses 2 relays and a 3-wire fan.

Johncuse

I have a 2009 Jeep Grand Cherokee Laredo and I can’t find the relay that’s supposed to be under the headlight on passenger side. Any help would be great