Hey y'all, I have just spent the last week searching through the forums in search of an answer to the cooling fan question. I've seen the problem on here, just haven't really seen the fix I am looking for. Same problem as many others, Fan doesn't come on. At all. Don't know if it runs with the A/C cuz I am waiting for a new compressor and currently have no A/C (and Yeah here in GA right now that sux).

Perhaps it's because I am female, perhaps it's because I am OCD (possibly caused by my gender) or perhaps I just like my stuff to work like its supposed to but I

A.) do not want to have to jump it (I currently have it jumped so the fan itself is fine)

B.) do not want a toggle switch so that in all my blondness I forget to turn my fan on. Sorry, I just don't think that way.


I have replaced the relays, I have replaced the temp sensor. the MAP was causing some other issues so that has also been replaced. IAC was pulled off and cleaned which usually will at least fix those long enough to show me another problem.

Could one of y'all please tell me what needs doing or point me to the thread I am missing that tells me how to get the fan working like it did in 1992?

Thanks in advance!

 

have you replaced the fan temp switch?

itwill be on the passenger sideof the block. the exhaust cooks the pigtail, and they disintegrate over time.

 

Oh I should have specified it's a v6 (yeah lame and it will be changed eventually but with gas prices right now it's not so bad). Isn't the switch only on the V8's?

 

Did you replace the temp sender that feeds the guage (driver side head, 1 wire), or the Coolant Temp Sensor (on the intake by the thermostat, 2 wire yellow and black)? The latter one feeds the ECVM the coolant temp info needed for it to control the fan.

Me? I'd invest into a seperate fan controller like a Flex-a-lite - it probes the radiator, has adjustable settings, will work with A/C when/if it gets fixed, etc. Mine was $100 (pricey I know), but worth every penny - never any fan issues again and 4 years later good as the first day!

 

I actually replaced the coolant temp sensor and what a pain it was, one of the previous owners of the baby had managed to break the heads off the screws so I had to take the throttle body off and drill them out. Of course I managed to break off a screw extractor in the process so now the sensor is cold welded to the intake and my manicure is ruined!

I really don't want to go with a separate fan controller and I think it's again just an issue of I want to make the fan work as it was designed. Should I look at the temp SENDER or would that just peg the gauge if it were out like alot of other chevy sensors do?

 

Did you check the Fan relay works?

 

The factory fan control system is overly crappy. Get an aftermarket fan controller from Summit. I got mine by Hayden for dual fans. Cleans ups the wiring pretty good to. You can also set you on off temps. No toggle.

 

See my signature.

 

If you have 2 fans you might have several sensors relating to temps

1# Temp switch for the main fan
the spark knock sensor if you have one has the same connector as the
temp switch for the main fan and are near each other on passenger side
of my motor...
#2 sensor for the dash gauge or light
the dash gauge/light only needs one wire usually a female spade
connector on my motors drivers side
#3 Temp switch for the second fan for AC or higher temps
#4 Temp sensor for the ECM for fuel injection

2 fans have 2 relays
they can be jumpered together so one temp switch turns on both relays.

 

Just one, it is for the ECM.

This is a fan switch, not a sensor and it is for the secondary fan, not the primary. Also, on a 92 3.1 v6, there is no fan switch anyways as they are single fans. The fan switch was present on the 2.8 as a redundant fan control.

This is a sending unit, not a sensor.

Answer #1 should be here.

The CTS (coolant temperature sensor) is for the ECM, the information from the sensor also allows the ECM to read the engine is 220°F to which, the ECM turns on the primary fan.

If you consider the newest system is almost 20 years old, I'd say they were designed pretty well to last so long. The electronics on these cars are years older than a portion of members on this site.

 

Hey im new to the whole thread thing but i have the complete opposite problem, my cooling fan comes on when i start the car! It just started a couple days ago after we replaced the thermostat. Also upon further inspection i noticed a smaller green wire that it looks like someone spliced into the wires coming off the radiator. it runs through the passanger door into the dash but havnt followed it all the way. I was thinking the previous owner wired it to come on when the car starts but that doesnt explain why it just started doing it. Please help! Also its a 1991 camaro 305 v8 tbi. Any help would be great, thanks!

 

if the fan switch goes out and is contantly grounded it will cause your fan to come on as soon as you turn the key. try relacing your fan switch. its on the passenger side head and should have a round mushroom like plug. no clue what the wire hack could be. the stock rad shouldnt have any wires at all going to it since it doesnt have any sort of sensor in it.


to the OP. i second the aftermarket fan control. way better than stock and adjustable... altough i run one that uses a sensor that screws into a water port instead of a probe in the rad. but thats just personal preference.

 

I finally got around to replacing the fan switch. The fan wouldnt come on at startup for the first day but now has started again. Could this be a bad relay?

 

the relay always has battery power going to it, the fan switch provides the ground. the only way the fan comes on is if the fan switch grounds the circuit at the temp designed to. if the fan switch wire grounds out at any point then the fan will come on, so you might wanna check and make sure it didnt come up against the header and melt trough and gound out or something along those lines.