978Jeep

Experiencing some issues with the cooling system. Here we go!.

97 Cherokee Sport 4.0

1. Tstat only reading cold at the first line above 100
(sometimes, when the car is started when cold and left to idle for an extended period of time it will move closer to the normal 210... however, once I start to drive it it drops back down to the first line)

2. Electric fan seems to turn on every 30 seconds or so now for about 2-5 seconds only... its also starting to cause my headlights to dim briefly when activated every single time and its getting pretty annoying (I will check grounds etc)

3. Heater blows warm and AC appears to defrost pretty well... However blower motor only works on HIGH.... (resistor or possible relay?)

Just purchased a 190 degree Tstat from NAPA.. comes with two and a gasket... will install this weekend.

Thanks for any advice

Bob_esper

hmm my fan does this also.. i thought it was normal

978Jeep

could be normal... i've owned the Jeep for 2k miles now and it was running normal temperature (note waterpump was replaced recently) and the fan didn't seem to come on as often.... so I'm getting a little worried multiple things might have to be addressed.

nickl

my electric fan does that too, but only when a/c is on or heater is set to defrost....weird but I have heard this is normal too.

978Jeep

I'm sorry guys but this is not normal. There is no need for the fan to come on every 30 seconds for 1-2 seconds at a time. It has to be some type of faulty sending unit/sensor... I'll try and post the solution to help this forum out

RENIXBEAST

Maybe its the temp sensor for the fan, the one on the t-stat housing

XJ4MEPLZ

your electric fan will turn on when the a/c clutch is engaged on the compressor. Your a/c is activated when on defrost. the short time seems to tell me that you are low on refrigerant and may have a leak.

Your resitor pack for the fan motor may be to blame for the high only setting, but the switch is also known to go bad on later models.

978Jeep

Played with the Temp sensor on top of the engine in between electric fan and motor and all seems to be back to normal... strange?

UNCC_99XJ

Nope, not strange at all. Chances are the connection for the temp sensor on the tstat are (or were) dirty, and by you playing with it you got the dirt off, hence why it's working again.

Same thing happened last month to my buddy's 98. Actually threw a CEL for a faulty coolant temp sensor when it spazzed out (engine was idling, all of a sudden idle dropped way down, the e-fan kicked on, then the motor stalled). All he did was clean it and it's been working fine ever since. His temp gauge would randomly drop to nothing from 210 and then come back up shortly before it threw a light

978Jeep

Thats strange, my 97' didn't throw any CEL as it read cold for almost 2 weeks. Electric fan would kick on randomly all the time but no stalling issues ever..