Jeep Aux Fan wont come on its own.

[Richard129]

My jeep has been running warm the last two summers, As I am told the 4.0 is known for running hot.
My question is what should I check to fix it. I for now have just wired it straight to the fuse box with a fuse taper kit.
I have a slight concern for the alternator and it constantly drawing that power when ever the jeep is running.
I have replaced the fan clutch thinking it might help the over-heating in stop and go traffic. it runs fine when you get going and once the sun goes down it runs ideally.


Anyone have any suggestions?

 

[jeep-N-montero]

Did you go through and check the normal cooling stuff like cleaning the radiator, condenser, the gap between them, install a new OEM thermostat, and test the fan relay?

 

[jmaxj]

unless i missed it, what model and yr of jeep?

 

[Richard129]

The year is a 96 Jeep cherokee. 4.0 H.O
The radiator is brand new the condenser I had no idea it would affect that.
The thermostat is a brand new Failsafe. ....
Where can I find the fan relay.
And thanks for the replies.

 

[jeep-N-montero]

The year is a 96 Jeep cherokee. 4.0 H.O
The radiator is brand new the condenser I had no idea it would affect that.
The thermostat is a brand new Failsafe. ....
Where can I find the fan relay.
And thanks for the replies.

So put in an OEM thermostat and google will show you where the relay is.

 

[jmaxj]

So do you know for sure the aux fan is/isn't working? Cause an xj really can cool without that fan. They over heat easy.

 

[N-Smooth]

I was going to say what do you consider overheating? They like to run around 210 and the fan shouldn't even come on until just under 220. There is a relay in the PDC and a sensor on the thermostat housing that will let it know when to turn on.

You can also just wire it to a relay and a switch. Mine is hooked up to the factory relay so it comes on automatically but I also have a switch to turn it on and keep it on. When I'm in Moab or Sand Hollow I have it on pretty much all the time just because I know it will get hot when I'm cruising around on dunes and whatnot

 

[Richard129]

I consider anywhere over the 210 line is a Little to far for me whats the highest, but still safe operating temp?

 

[Richard129]

So do you know for sure the aux fan is/isn't working? Cause an xj really can cool without that fan. They over heat easy.

So I checked the thermostat sensor, When unplugged the fan would come on.... Im guessing as a I.C.E if it doesn't detect a temperature it just runs it Just in case.

So would I still want to check the relay since the Fan came on when unplugging the front temp sensor.

So put in an OEM thermostat and google will show you where the relay is.

Do you really think that the failsafe thermostat could be the issue??

If so would you still go for the "OEM" Thermostat or a alternate temperature thermostat.
I've heard that the alternate temp ones will chug gas a bit more.....



Side note: Does anyone know about a Toggle kit for the fan that has a Tempeure probe that you slip down the top hose and you set the temp you want the fan to toggle on at.

 

[N-Smooth]

210 degrees is operating temperature. I don't even worry about my jeep until it's at 230. If 220 was a problem I don't think the engineers would have made the fan come on at 216-218 or whatever.

Not sure if the system bypasses the temp sensor or not.

I think he was saying you should get an OEM temperature thermostat (195) but maybe he actually means jeep brand... I dunno. I don't think it matter personally, I just got a 195 from the Zone.

There are lots of electric fan kits out there that have probes you can install and regulate for different temperatures.

 

[thenag]

I was going to say what do you consider overheating? They like to run around 210 and the fan shouldn't even come on until just under 220. There is a relay in the PDC and a sensor on the thermostat housing that will let it know when to turn on.

Yeah everybody says "they run hot" but 210 is what it is designed to run at. There are things that you can do to help cool down the engine bay, vents, remove rubber seals etc. (Just don't be one of those guys that thinks they can "beat the engineers by removing your t-stat" your EFI won't run efficiently...)

You can also just wire it to a relay and a switch. Mine is hooked up to the factory relay so it comes on automatically but I also have a switch to turn it on and keep it on. When I'm in Moab or Sand Hollow I have it on pretty much all the time just because I know it will get hot when I'm cruising around on dunes and whatnot

I keep forgetting to make that mod, this last moab trip I just ran the a/c to get the aux fan on

Nathan
http://www.rme4x4.com/showthread.php?83436-Nathan-and-Tanja-s-99-XJ-Build-up

 

[jeep-N-montero]

So I checked the thermostat sensor, When unplugged the fan would come on.... Im guessing as a I.C.E if it doesn't detect a temperature it just runs it Just in case.

So would I still want to check the relay since the Fan came on when unplugging the front temp sensor.




Do you really think that the failsafe thermostat could be the issue??

If so would you still go for the "OEM" Thermostat or a alternate temperature thermostat.
I've heard that the alternate temp ones will chug gas a bit more.....



Side note: Does anyone know about a Toggle kit for the fan that has a Tempeure probe that you slip down the top hose and you set the temp you want the fan to toggle on at.

I was referring to both OEM brand and temperature, there are a few tests proving OEM is the correct opening temp and spring pressure.

210 degrees is operating temperature. I don't even worry about my jeep until it's at 230. If 220 was a problem I don't think the engineers would have made the fan come on at 216-218 or whatever.

Not sure if the system bypasses the temp sensor or not.

I think he was saying you should get an OEM temperature thermostat (195) but maybe he actually means jeep brand... I dunno. I don't think it matter personally, I just got a 195 from the Zone.

There are lots of electric fan kits out there that have probes you can install and regulate for different temperatures.

 

[SLC97SR5]

I don't have any real input other than my wife rocked an XJ for a few years and overheated it many, many times. Overheated to the point that the engine shutdown...let it cool down, start it back up and it always made it to the mall.

 

[Richard129]

I don't have any real input other than my wife rocked an XJ for a few years and overheated it many, many times. Overheated to the point that the engine shutdown...let it cool down, start it back up and it always made it to the mall.

Te he Must make it to the mall!!!