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what temps do my AUX fan come on at ?

dan89XJ

NAXJA Forum User
Location
Oregon
Hi, I am wondering what temps my AUX electric radiator fan will turn on at ? I just upgraded my 89 XJ cooling system to 92 parts.. with the temp switch at the thermostat housing. at 210 The aux fan doesn't come on. However when I turn the AC or defrost on.. the fan starts up... is this normal ?

Thanks,
Dan
 
The 1988 FSM electrical manual says 190 degrees ... but I don't believe it. Everything else I've encountered says 217. 190 might be the temperature at which it shuts off once it has been activated.
 
The 88~90 renix system the cooling fan will come on at 208*F and turn off at 195*F... The 91+up will come on at 217*F and turn off at 208*F I found this out when I did my swap, I finally searched and found the tube that goes in the lower hose for the renix sensor instead of usuing the one in the t-stat housing...
 
In the later system, the temperature sensor in the thermostat housing isn´t a switch, like the one in the closed system. It is a sender and the switch is someplace else, most likely, in the ECU through a relay.
Í´ve tested two of the thermo switches in the lower left of the radiator, they were both old, but both switched at 209 F. a newer switch may switch later.
If you put a switch in the thermo housing, there was a part number for a Chev. thermo switch that appeared in a recent thread (that fits in the thermostat housing), remember the coolant going in, is some hotter, than what should be coming out.
 
Last edited:
Clean-RC said:
The 88~90 renix system the cooling fan will come on at 208*F and turn off at 195*F... The 91+up will come on at 217*F and turn off at 208*F I found this out when I did my swap, I finally searched and found the tube that goes in the lower hose for the renix sensor instead of usuing the one in the t-stat housing...

I was writing while you were posting :wave: Our numbers seem to agree.
 
The chevy one doesn't work that well either... I tried all this stuff a year ago... I have since put in a electric fan controller that we use on street rods with adjustable temp control... I also have the lower hose tube that the deisels used in the xj for the fan switch... My jeep never gets over 210*...finally...
 
Clean-RC said:
The chevy one doesn't work that well either... I tried all this stuff a year ago... I have since put in a electric fan controller that we use on street rods with adjustable temp control... I also have the lower hose tube that the deisels used in the xj for the fan switch... My jeep never gets over 210*...finally...
I don't get it. You have 2 switches for the e-fan?! What did I miss? I would love to be able to turn the e-fan on my '89 sooner than 208, now that you have corrected the 217 number for my Renix 4.0

Thanks _ Maz
 
5-90 said:
With the RENIX, it's easy to install an override for the E-fan
5-90
I understand the override switch, but I got the impression that there are 2 "automatic" temp-controlled switches that Clean-RC was talking about.

_Maz
 
8Mud said:
In the later system, the temperature sensor in the thermostat housing isn´t a switch, like the one in the closed system. It is a sender and the switch is someplace else, most likely, in the ECU through a relay.
Í´ve tested two of the thermo switches in the lower left of the radiator, they were both old, but both switched at 209 F. a newer switch may switch later.
If you put a switch in the thermo housing, there was a part number for a Chev. thermo switch that appeared in a recent thread (that fits in the thermostat housing), remember the coolant going in, is some hotter, than what should be coming out.

So, this sender on my thermostat housing is not doing anything for me ?

I always figured the water coming out of the engien would be hotter than the water going in since the water has been cooling in the radiator.
 
ok what i recomend for the renix is take a on/off switch from your hardware store-4 bucks, use 10ga wire about 15 ft-5bucks, and tap into the connector for the fan switch at the radiator... The renix uses a swtich to activate the cooling fan, the HO uses the ECU to activate the cooling fan via temp sender in the t-stat housing... with the on/off switch you have the luxury of sitting in traffic and allowing the fan to come on at any given time when you want it too... I hope this clarifies stuff better...
 
8Mud said:
In the later system, the temperature sensor in the thermostat housing isn´t a switch, like the one in the closed system. It is a sender and the switch is someplace else, most likely, in the ECU through a relay.
Í´ve tested two of the thermo switches in the lower left of the radiator, they were both old, but both switched at 209 F. a newer switch may switch later.
If you put a switch in the thermo housing, there was a part number for a Chev. thermo switch that appeared in a recent thread (that fits in the thermostat housing), remember the coolant going in, is some hotter, than what should be coming out.
What is the correct procedure to test the thermo switch.....I think mine is the reason my fan doesn't work,because it works when I hook it up direct to the battery.
 
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