Hey guys, ever since I've owned my Cherokee (a few months now), the electric fan has been acting strangely. It kicks on and off every 30 seconds...like it will go on for 30 seconds, then shut off for 30, and so on. I'm not really sure what could be causing this...a bad relay? switch? help me guys its starting to really annoy me!

 

Is a/c on? Efan cycles on with the compressor and if compressor is cycling on/off rapidly, system could be low on refrigerant.

 

the a/c doesn't work but the fan does the same whether or not it is turned on

 

I don't know......efan also turns on at 218F coolant temp and off at something like 209F. Seems like it would take more than 30 seconds or so for coolant temp to rise/fall to activate/deactivate the efan. Somebody will be along shortly to clue us both in.

 

Sounds like a bad relay to me.

 

from the minute i turn on the jeep from a cold start it will start cycling. It might be less then 30 seconds. it seems like it starts spinning for like 8 seconds then kicks off and slows down, and once it hits a solid stop it will kick right back on

 

From a cold start? Check the fan switch first then. Coolant temp sensor mounted on the thermostat housing

 

what should I be looking for? just wear and corrosion? or should i be testing it with something?

 

testing with a meter works fine, but I would swap out the fan control relay first, just to rule out the gremlins. Sway the fan relay with the fog or highbeam relay and see if that solves the problem.. If it does then you just saved hours of diag time and you go get a new relay.

 

http://www.lunghd.com/Tech_Articles/..._Diagnosis.htm

 

what year

 

its a 99

 

have you checked for codes even if no light is present

 

i would suspect a problem in the coolant temp sensor it switch the fan on andoff its on the thermostat housing ,unless there a ac related issue