I have a 98 cherokee sport with an auto tranny. The electric fan that cools the tranny fluid cycles very frequently and at odd times. For example; when i have been driving for a while, stop for 20 min then start it back up again the fan will cycle right away for 3-4 sec every 15 seconds. The reseach I have done so far tells me there is a temp sensor and a temp sender. Would it be a matter of replacing these or is there something more devious at work?
Thanks

 

The electric fan is not for the trans fluid.. it's your seconday or auxillery cooling fan. This cycles on/off when the HVAC is on or your running temps hit 220.

 

when you shut your jeep off the engine goes through a heat soak the temp gets hotter, around 225-240.. so when you restart your jeep there is going to be a warm sputter and your e-fan is going to be on..

 

Sorry, I realize it doesnt cool tranny fluid, but it does cool coolant that runs through the tranny. right? I would understand it coming on and staying on until the temp reduces, but it cycls pretty quick... seems weird.

 

It does cool the tranny fluid as the tranny fluid is circulated to a tank inside the radiator, then back to the tranny.........no engine coolant circulates to the tranny. Quick on/off cycling of the electric rad fan sounds like the A/C compressor is on and it's low on freon.

 

hes got the ticket. or your driving around with your defrost on

 

K, so it is a remote tranny fluid cooler.... i see the hoses going back there either way , its just getting warm up here so definitely not rockin the a/c. The defrost on is definitely possible. The correlation is?
thanks again guys

 

the defrost will actually kick the ac compressor on which makes the elec fan cycle. something about the ac going defrosts faster? i duno but i def makes youe elec fan turn on. I use it on the trial to control my stock elec fan

 

No luck. Not running a/c as previously mentioned, nor is the defrost on. the temp is around 95-100 celcius and that ***** kicks on and off non stop... bizarro

 

this is the wiring diagram. check relay.