i have been having some problems with my lumina. only paid 600 for it . but anyway. recently replaced raidiator hose , thermostat, and water pump. but while workign on these things . i noticed no matter how warm the car is. i never see the fans come on. i have not had this car long. but today after replacing the water pump. we ran the car for a bout an hour. just sitting there parked. ran heat full blast. defrost. fans never came on. i left it running . the drove it a couple miles home. before turning off the car i checked under hood. and nothing running. also . the day i replaced the hose and thermostate. it was dark at that time. i turnd a/c and the clutch was so hot it was glowing. which i was told is why i over heated.so i was told my ac/ clutch is also out. that as long as i dont run my defrost or a/c . i'm ok. well this was before the water pump. but today after replacing that. i ran , my heat and defrost both each for a pretty long time. and they worked. and nothing seemd to happen . that shouldnb't of. but my ac was bloing but only wamr air. but under the hood . nothing looked hot or overheated this time. could my water pump have anything to do with my ac clutch. and does that effect my defrost like im told. i no i cant explain very well. but please try to makes since of my ramblings . and please share any ideas or any ifo . thanks you guys.

First of all always post the year and engine, second he fans come on based on ac pressures when in use, and/or the temp reaching 222 degrees, a scanner would tell you the actual temp, or the use of a non-contact thermometer reading at the temp sensor.

If you don't bleed the air from the cooling system after repairs like that, an air pocket will sometimes cause the sensor for the fans to not sense temp correctly and they won't turn on, even when the motor gets hot.

My '97 3.1 will run a loooong time idling before the fan ever turns on, probably 20 minutes or more.

Anyway if you wanna see the fan turn on, don't run the heat...all you're doing is substituting blowing heat out of the system from the heater core for blowing it out of the radiator...if yours is like mine, the fan probably never would turn on, idling with the heater on.

Put the heat control on cold, A/C off, run to operating temp, then raise idle to 2000 rpm for a couple of minutes...I'll bet you'll see it turn on, may be a few seconds after letting the rpm drop back to normal... If you start to see any strong activity happening in the coolant reservoir, stop...it may be getting too hot.

This car have a temp gauge?

If the A/C clutch has problems you'd just as well unplug it, that way you won't engage it no matter what position you set the control at.

I can't think of any reason the A/C clutch would affect the water pump, unless it was dragging so severely it was slowing the serp belt. But you'd know it if that was happening...all hell would be breaking loose..

i have a 1991 chevy lumina . with a 3.1 v6 . and i ran the car today in the drive way for at least an hour . and my fans still never came on . i didn't run the heat or anything. so far nothing i do seem to triger them. and i was looking at my fuse box under the hood. and it said first and secondary cooling fan relay. and from what i looked at at autozone. are these the releys i would need to replace. i thought they were just fuses. and the relay would be somewhere else. and they dont loko like small fuses . there square and a lot bigger.

Yeah that's the relays. You could try swapping them if they are the same P/N and see if anything changes...