ChevyTuffD.A.

I have noticed that since i got my car running again a few months ago that my fans are always on. I started the car last night for the first time in 2 weeks and it was about 30 degrees outside. Anyway, I start it up and after 2 seconds of running i hear the fans click on and they dont ever turn off until i turn the car off. From what i have read here on the boards this is actually a good thing regardless of why it is happening. What do u guys think??

meengreen 94z

Check and make sure your coolant temp sensor is plugged in.

Birdman7389

Is your SES light on? I know certain codes will cause the fans to come on.

OBE1 95Z28

It's not a "good thing" that your fans are on. Something is wrong, either you car is running in limp mode (default settings when the computer detects a malfunction) or as stated above, your temp sensor and/or wiring is faulty. Get you car scanned for failure codes.

94blackz14.2

Do you have the defrosters on. I know that when my air conditioning compressor comes on that the fans come on fully blast as well. Something to consider.

ChevyTuffD.A.

As far as I know the temp sensor is plugged in, my temp guage works just fine. I dont have any SES lights so would I have trouble codes to look up?? Also what is "limp mode" and does it hurt performance or something??

MentalCaseOne

Dude would you believe me if I told you that even though your temp gauge is working just fine your Temp Sensor would still be disconected??

Also check your MAF connection. My fans come on if I disconect my MAF.

****Pssssst. The Dash Temp sensor is ran from a separate temp sensor. Check the one in front of the Water pump. Although I dont think my car will start without it... I have not tested it yet.

Limp Mode. if something goes awefully wrong or a sensor takes a dive the puter reverts to whats called Limp mode... meaning for every cranck revolution will inject a predetermined amount of fuel and will use minimal sensor imput. Just to get the car running and get you back home. Correct me if I am wrong but it wont even read oxygen sensors in Limp mode?? My scanner gets readings from the O2s but the car sounds and feels diff.. so I guess its not making corrections by reading O2s?


Marvin


Marvin

#7

I am pretty sure the fans are triggered by problems that may come up. Kind of a default for problems but yeah usually accompanied by SES but not allways. In my cases! 2 times this has come up. Now when this happens I immediately look for something unplugged.

The first time was after I removed the A.I.R. system. The continuious fans werent trigger by just the pump removal. But when I removed the air pump FUSE in the engine fuse box. It happened. I was stumped for awhile on that one.I had just removed/hacked alot of the interior wiring also.So was stressed JUST A LITTLE Eventually Popped the darn fuse back in the box on the hunt and the fans stopped.

Next was when I wanted to run the car w/o all the MAF,IAT and tube and elbow. The fans ran continuiously then also. But immediately stopped upon the reinstallation of the intake and the MAF and IAT plugged back in.

Look for something unplugged and maybe check the fuses in the underhood box for missing and/or burnt ones.

Good luck.I would not say that fans running all the time is good. Dont know if they are designed the withstand that for to long who knows ...not me. I did not like it one bit. Of coarse I dont like it when something is wrong. And wont dismiss it as a good thing either because of lasiness I think you should find out whats wrong

T.

edited to fix some of that link crud that just shows up

WhyHelloOfficer

Is the idle fairly high as well? If it is idling high and the fans are on it is in closed loop mode which means one of your sensors are not connected properly. Sometimes you'll have the SES Light and sometimes you won't. The motor runs are preset inputs and because one or more sensors are not reading. So it doesn't want to overheat or something else along those lines. So it runs the fans all the time and idles high.

It is also possible that you could have botched wiring up a manual fan switch? I'm not sure if you have one or not, but if it isn't wired correctly your fans could possibly be running all the time -- or not at all.

--Just some things to think about.

Joe Blaze

ChevyTuffD.A.

Ok , I will go out and look for connections unplugged. My idle is at about 1,000 rpm's at start up and eventually makes it down to about 750 after it is fully warmed up and i have drivin it. My car seems to run rich at start up hench the black smoke the will puff out till the car warms up also. One of my o2 sensors is fairly new and is a Bosch, I have heard these arent the greatest sensors so could it not be working right?? I also have deleted the AIR system but i beleive i do have a fuse in there. I will go give it a full inspection and let u guys know. Thanks alot with the responces, Dustin.

Beyonce Knowles

I'd rather have them always on than always off. There are plenty of people on this board who would be happy to have your problem. Try having them not come on in a trafic jam going into Orlando. Now that sucks.

shoebox

If they are always on because of a trouble code, then that's no good.

ChevyTuffD.A.

Shoebox i cant believe u visited my thread and didnt provide any insight Come on your smart u gotta have an idea.

shoebox

I thought you had already gotten some good suggestions to check out. Scan for trouble codes.

ChevyTuffD.A.

Ok i can do that. Will i still possibly have some trouble codes even tho i dont have any SES lights?? If so how do i go about scanning for them??