Try replacng the sensor. Also, the jeep should realy never run hot enough to kick that fan on unless you have other problems. Id check your fan clutch it's probably bad.

 

didnt see your post sorry...
anyways yeah i replaced the coolant sensor in the tstat housing with another one and it didnt change anything...

funny thing is i tried to get it to get warm enough to kick the fan on but couldnt get it hot enough i gotta replace my other temp sensor in the head for the gauge because its broke and works on and off...

i was going to in the past but its annoying to find that sensor no one carries it for some reason..

i hate to start buying all these sensors right now because im in the works for my 4.7 stroker and would rather put all new stuff on that engine.

if anyone gets a idea let me know like i said right now im thinking pcm

 

i also just jumpered the blue and pink wire out of the computer and the fan kicked on so im assuming this means my computer is bad?

 

Your computer doesnt control the electric fan i dont think? You should have a switch i believe towards the back of the motor maybe on the head that kicks the fan on. I cant remember now. My 95 XJ is the same way

 

Sounds kinda basic, but if you can get your hands on a known-good fan, hook it up to your wiring connector and retest--this just to make sure your fan motor isn't bad. I didn't see where you wired 12v directly to the fan to check it for at least 30 seconds of operation....couldn't tell if you actually ran the fans for more than a few seconds....also to make sure that the AC clutch is actually engaging, connect a jumper across the connector on the accumulator, (after unplugging from the LP cutout switch) and then turn on the AC with the engine running.

 

To thecrew2999....I found some good troubleshooting info in a manual I have specific to the '93 cooling fan. Maybe you already have this, but if not, here it is.....Hopefully this isn't too much to post:

ELECTRIC COOLING FAN
On Cherokee 4.0L engine with heavy-duty cooling and/or air conditioning, an auxiliary electric fan operates whenever engine temperature exceeds 190 degrees F or if AC is turned on. If the Powertrain Control Module (PCM) detects a fan control circuitry problem, a fault code will set.

TROUBLE SHOOTING & TESTING
Electric Cooling Fan Circuit
1) Ensure fuses No. 4 and 6 on Power Distribution Center (PDC), near battery, are good. Ensure fan operates. See MOTOR under
COMPONENT TESTING. Remove cooling fan relay from PDC. Start engine. Using a test light, check for power at terminal No. 2 (Light Green/Red wire) of PDC. If test light does not illuminate, repair open circuit in Light Green/Red wire between terminal No. 2 and fuse No. 4.
2) Connect a jumper wire between terminal No. 2 (Light Green/Red wire) and terminal No. 4 (Light Green wire) on PDC. If fan does not operate, leave jumper wire connected. Unplug fan connector on left side of fan shroud.
3) Using a test light, check for power at Light Green wire on fan harness connector. If no power exists, repair Light Green wire between fan harness connector and terminal No. 4 on PDC. If power exists at Light Green wire, repair open circuit in Black wire between fan harness connector and ground.
4) Turn ignition off. Reconnect fan motor connector. Remove jumper wires. Reinstall relay. Connect Diagnostic Readout Box II (DRBII) to engine diagnostic connector. Connector is located in engine compartment, next to PCM.
5) Start engine. Energize fan relay circuit by warming engine until coolant temperature is higher than 190 degrees F.
6) If relay does not click, put DRB-II into voltmeter mode. Measure voltage at cavity A1 (Dark Blue/White wire) in relay connector. If voltage is less than 10 volts, repair open circuit in Dark Blue/White wire between cavity A1 and fuse No. 6. If voltage is 10 volts or more, turn ignition off and reconnect relay.
7) Unplug connector from PCM. Examine connector. If connector is okay, turn ignition on. With DRB-II in voltmeter mode, measure voltage at terminal No. 31 (Dark Blue/Pink wire) on PCM harness connector. If voltage is 10 volts or more, replace PCM. If voltage is less than 10 volts, repair open circuit in Dark Blue/Pink wire between PCM terminal No. 31 and PDC terminal No. 5.

COMPONENT TESTING
Fan Motor
Unplug fan motor connector at left side of fan shroud. Connect a jumper wire from terminal "B" (Black wire) of fan motor connector to a known good engine ground. Using another jumper with a 25-amp in-line fuse, supply battery power to terminal "A" (Red wire) of fan motor connector. Service fan motor if it does not run.

Fan Relay:
1) Remove relay from Power Distribution Center (PDC). Connect a self-powered test light between relay terminals No. 2 and 4. Test light should indicate no continuity. Leave test light connected.
2) Using a jumper wire, connect relay terminal No. 5 to a good ground. Using another jumper with a 15-amp in-line fuse, supply battery power to relay terminal No. 1. If test light does not indicate
continuity, replace relay.

Hopefully this info actually applies to your vehicle configuration.

 

i did all those tests and everything passed the fan works fine when its jumpered/coolant sensor unplugged/or the blue and pink wire leading to the computer is grounded so its working threw everything just the computer isnt grounding it out for whatever reason...

i have heard the fan does not work at all if the a/c dont work can anyone verify this?

i know the a/c isnt engaging the clutch at all.. i plan to jumper the plug to see if it kicks at all for all i know it could be bad inside the hvac in the dash controls.

 

jumpered the a/c plug and it isnt clicking the clutch so either its burnt out or i got some other issues with the a/c

still no luck with the fan tho

 

Do you NEED the electric fan to kick on normally to keep your jeep cool? if you do then like i said above, you have other issues. It should pretty much never come on unless you are using the AC. When i first bought my XJ the electric fan came on all the time. Truck ran a little hot also. Turned out the clutch on the mechanical fan was shot. Replace it and never heard the electric fan kick on ever again. Ran cooler than it ever did. Also put all new hoses on it, new antifreeze, and a new 195* thermostat. Obviously you have to fix your fan problem but you may want to look into the rest of your cooling system. If you have never replaced your clutch it's a safe bet that it's bad. Only about 50 bucks and an easy thing to do.

 

thanks for the reply but i wanted to hook up a taurus fan to the stock electric fan wiring and get rid of the mechanical fan setup..

my cooling issue is the extreme heat this year and the fact i dont have a fan shroud which was broken in many pieces so im sure its not pulling the proper amount of air.

i changed t stat, water pump and coolant already because the water pump died on me.

now you mention it tho i suspect my fan clutch going bad being i dont hear it hum like it used to..
either way like i said i want to hook up a taurus fan and i wanted to use my factory electric fan wiring.

granted i could go out and buy a controller and such to do this but if i got it from the factory why not use it..

edit:
now i think about it, what computers can i try and sway in?
does it have to be a 93 cherokee with the same option or can i use a wider number of PCMS ?
im going back to thinking i possibly have a computer issue

 

Have you checked the air gap on the electric clutch? Look for some recent posts on this subject. If the air gap exceeds .035" or more, the clutch plate won't be pulled into the electromagnet so the compressor won't turn. Use feeler gauges to check the gap and then report back. I believe the range should be .016-.031". I try to set them around 0.020", depending on what shims are available....

As to the fan clutch, I assume you know how to check this, but if not, (and while the engine is hot, but not running), spin the blades by hand. If the fan rotates several times or "free-spins", then the fan clutch is bad and needs to be replaced.

And I might be repeating something already said, but did you connect a jumper across the LP cutout switch wire connector? I use a small paper clip for this. If the R134 level is low, this will close the circuit to the AC clutch.

As far as the PCM, most folks I've spoken to report this is not a common problem and they are very reliable.

 

thanks for the reply but this fan works when you unplug the temp sensor or ground the wire out on the computer that controls the fan on and off or jumper the relay so the function of the fan does work just for some reason the computer isnt giving the signal to do so...

i also thought about checking the grounds and cleaning them all up, while im at it im gonna use dieelectric on all connections to be certain. weird thing is tho nothing else really seems to be a problem. sure it misses at high rpm but thats unrelated.

i guess i might have to check out wiring as well since it looks like someone tapped into the coil for a tach wire and i got another for what appears to be the trans harness.

i did paper clip the plug for a/c pressure switch with no luck so it appears i might be hunting down the problem for that later on as well.

as for the PCM like i said if it isnt any wiring issues the only thing i got left would be the PCM so far it all points to that.

i could really use a wiring diagram as well but the xj service manual i got dont have the full wiring nor does any chilton or hanes ive seen.

 

DO NOT even think about using a taurus fan on the stock wiring. You will burn your jeep to the ground. They pull WAY to much amperage for that fan. You can use the stock wiring as a trigger fo rnew high amp relays. All 10 gauge wiring and 2 40 amp relays. One for low speed one for high speed. That will work great as long as you do it right.

 

yeah i already knew that sorry guess i should have gave more detail on what i ment.
i basicly was only gonna use the stock fan wiring for a trigger.

I have some wiring diagrams for a '93--if you can give me an email address, I'll send you what I have. I think one of the wiring chapters has 11 or 12 diagrams. Do you have the same one?

sure thecrew2999@yahoo.com ill see if its what i got. all i remember is its like 3 diagrams

 

Just wanted to be sure. Taurus fan is an awesome conversion works great just suck up a lot of juice. You may want to look into a better alternator also. The 5.9 grand cherokee came with a 160 amp alternator which barely keeps up with the OEM electric fan. The OEM electric 5.9 fan pulle pretty much the same as the Taurus fan. With that said keep in mind the stock XJ alternator is 90 amps.

 

i always believe more amps is better to have when needed but i got 2 taurus SHOs and one is 120 amp alt the other is 90 amp alt, the 90 amp one has a single fan for the manual the 120 amp has dual fans for high and low speed.

basicly what im getting at is the stock alt will do it seeing the jeep dont have the high output DIS coil like the SHO does which really sucks power down.

the reason ill be ok is because the fan only kicks on and off every few minutes enough time to keep the charge up. besides the jeep dont see a lot of idle time, its a work horse really..

thanks tho

just wondering is the 160 amp alt able to be converted to a 4.0 cherokee?