sycoglitch

its the mechanical fan that spins hard when its hot. The electric fan you will have to watch and listen for at 218

NewJerseyXJ609

Here's what you do to test your aux fan. Assuming you have a late model xj.

Buy a 470ohm resistor from radioshack. Get the jeep to operating temp and shut it off. While the jeep is off unplug the coolant sensor on the thermostat housing. Plug the resistor in the connector end, not the sensor. Make sure the both ends of the resistor are touching a terminal. Then turn the ignition on. Your temp guage should read roughly 235 deg and the aux fan should run.... By doing this your testing the fans whole circuit relay and all. If the fan comes on you know everything is good.

You can also simply unplug the fan and feed power and a ground to it. But my first test is very easy and will test everything.

Make sure to turn the jeep off when you take the resistor out and plug the temp sensor back in. Doing it the way I've explained will cause no check engine lights if done correctly.

For the mechanical fan: if the clutch is still good in it you should not be a leader to spin it excessively by hand. It should stop when you spin it. It should have drag. If it spins too freely the clutch is bad and the mechanical fan needs replacing. You should hear it spinning like a jet engine when you take off from a stop. They are loud when they work properly. You can hear the air they push.

a_shirey

How mch fluid goes ina AW4?

ScikoFaery

My temp never goes over 210
Yes the blower fan works and I supposedly have a new heater core I would love to have ac but at the same it kills my gas in this beast and I dont need worse mpg than I already have lol

NewJerseyXJ609

See my last post for testing the aux fan

lunablue

Hey Everyone,
This is my first time posting, though I have scoured these pages quite a few times!
I have a 2000 Cherokee Ltd. 4.0... I am not totally car illiterate, but I am somewhat of a newbie when it comes to working on my Jeep.
Here is the problem.. Long story short, I was having issues with it running a little hotter than normal, took it in, got a coolant flush (it was gross). They said it should fix the problem... it didn't. Ended up reflushing it myself..(they didn't do a great job), changed the thermostat, cleaned the hoses and reservoir. Put it back together, ran it with the rad cap off for a few minutes and it seemed to be doing fine... good circulation, no leaks anywhere. Shut off the car, put on the cap, started it back up and it started leaking.. I pinpointed it to a compression fitting on a pipe that runs from the back wall to the side of the radiator. Not sure what that pipe is or how to fix it... Thought it might be the trans cooling line, but from what I've looked up, that's the pipe-to-hose that runs right above this pipe. Any ideas on a quick fix? Should I just take the whole darn thing off and replace it? I've heard taking off a compression fitting is a pain, even with the special tool....

Outlaw Star

Welcome to the forums. The only coolant hoses that run to the firewall (back wall) should go to your heater core. The lines that run to your radiator are transmission cooling lines. They are easy to replace as well. For compression fittings, use flare nut wrenches to help prevent stripping. (Try to loosen it while the lines are still warm, it will be easier). Good luck.

Eagle564

So im looking at my electric fan and all i see is 2 wires leaving it and going into another connector, then going to the main bunch that runs along the side. I ran the vehicle til it got past 220 and no fan turning on. What should i check other than connecting it to power?

NewKindOfClown

It's very common for the trigger to stop working. Many people (such as myself) wire it to a switch. I don't know exactly what to test, though.

Eagle564

Alright. Well where is said switch and is it replaceable? Id wire it to a switch but who knows of thats the issue, plusnmy fiery hatred for eletrical crap. The dang thing worked like 2 days ago too..

Wired to battery and it kicked on. What sensors are responsible for turning it on that i could replace? Or just switch wire it?

ScikoFaery

i dont have the money to buy one of those things unfortunately
my main fan def work she roars like the dinosaur she is when i take off haha

94XjSport94

They MIGHT be $3

NewKindOfClown

I'm gonna preface this by saying I'm no electrician. I wire things to get the job done, with no regard for possible failures.

Renix has a temp sensor on the radiator to trigger it, and I think HO is on the thermostat housing. I grounded the - wire near the fan and ran the + wire to switch, then to the battery. Simple On/Off. If you do that, make a quick disconnect near the fan using spade connectors. It'll be much easier if you have to remove it.

ScikoFaery

oh ok thats not to bad lol

btw where the heck are the spark plugs under the valve cover??
i stared that engine down for like 20 mins yesterday and didnt see any sign
in my car they are right on top wires running out and all lol

Eagle564

Oh thats waaay more simple than i expected. Ill take a crack at it tomorrow.

Trying to remove my flares now... i didnt know tgere are steel plates that are studded in with welded nuts on the other side. Cant remove the damn things. I cant believe im doin this to my baby lol. She looked so good with her flares. My tires are just too big dang it.