Cooling Fans Not Working

**thewaitinggame** · 08-25-2011

Looking for advise on what to check and test for my cooling fans. Its a 03 Grand Prix, 162,000 miles. Yesterday sitting in traffic on my way home from work I happen to look at my temp gauge and was very high, I would say about 240 or so. It was near that last long line before the red area. Usually it gets about 210 and just over that the fans kick on like its supposed to. It did go down when traffic picked up but by the time I got home it was back up. Popped the hood and noticed the fans were not running. So I looked on here for answers and also google but never really found out why this would happen.

I checked the fuses for the fan and also read the motors could be bad and to check it I would need to jump them from the battery. Im not real good with electrical so I tried that but I assumed I was doing it wrong because I didn't get it to work. Came back on here and saw some peoples fans would run when the AC was on. Tried that next and sure enough within 20 seconds of running the air the fans were running. I take it the fans aren't bad and its something else.

So what more should i test or replace? I also read the relay could be bad but didn't check it because I didn't know where it was, its one of those blocks in the fuse box? I may just replace it. A guy I work with said maybe the T-stat could be bad. I also came across a temp sender could also be bad. Would it be a good idea to start by replacing these all first?

Any other suggestions would be appreciated or if someone also had this problem and found the solution , I would appreciate that info also. thanks

**BillBoost37** · 08-25-2011

Try swapping the fan relay with the ac relay and see if the Ac no longer works. If so, your relay is bad.

**thewaitinggame** · 08-25-2011

cool thanks I will try that when I get home today. I drove my wifes car today but just to be sure I should avoid driving it until I figure it out? or can I still drive it as long as the temp doesn't go that high or if its cool out. Because come Monday I have no choice but to drive it, she works a few days so I cant use her car on some days. Hope I fix it by then

**Curt7** · 08-25-2011

Avoid driving it at all costs. Just overheated my engine. Total was approx 1300 bucks for a used engine, engine swap labour and parts. All because of a bad temp sens

**bps02gtp** · 08-25-2011

triple check to make sure your coolant level is where it should be. a thermostat is 10 bucks and at that mileage if you havent replaced it in a while it probably wouldnt be a bad idea all tho that wont fix your fan issue if its screwed. if its not the relay it could be your temperature control sensor.....and that might not be the correct name but i know its something like that lol

**thewaitinggame** · 08-25-2011

ok i just got home, coolant is good and yeah maybe a thermostat is probably a good idea to get. The one problem Im seeing about switching the relay with the ac one is they are different sizes. I have a #9 cooling fan, #10 cooling fan 2 and #12 cooling fan 1. The 10 and 11 are a 4 prong and the 9 has 5 prongs. These are the biggest relays and are square, the AC relay is smaller and rectangle. So not sure on how to test the relays now. The only other one thats the same size is the ignition main.
I was thinking of just replacing the temp sensor too. It screws in right by the thermostat so might be good to do that also. Any thoughts on how else to test the relays and which one to check without buying 3 new ones?

**thewaitinggame** · 08-25-2011

ok i went to buy the parts and the guy told me at orileys that electrical parts are non returnable. I told him whats going on and he also said its probably temperature sensor because they run with the AC on so the relays should be fine. He said unplug it and if the fans run then the sensor is bad. I just did it and the fans came on full speed. I guess I will buy that part tomorrow, replace it and bring the car up to normal temp and see if they kick on.

**bps02gtp** · 08-26-2011

thought so. good luck

**thewaitinggame** · 08-27-2011

Looks like it was the temp sender sensor. Installed it this morning and brought the engine up to 210 and the fans kicked on. It was pretty bad to do though, took me about 3 hrs to do but I also changed my oil. For the sensor, I realized that I didn't have a deep 3/4 socket so I went to buy one but the one I bought was too long. My open end wrench didn't have room either. Its a very tight area and with a universal on, it wouldn't even fit. Took that back and bought some offset wrenches but those too didn't work. Then I thought to take off the thermostat housing because I am changing that out too. Good thing I was because it gave me a little more room to get and open end wrench in there and do 1/8 -1/4 turns until I could loosen it by hand.

So if anyone else has to do this, take off the thermostat housing and you can get to it with an open end wrench. I wasted a lot of time running around trying to find a tool that could get in there better and I didn't really need to at all. I really hate when something so simple looking turns into a few hour job! Thanks for the help again.

**bps02gtp** · 08-28-2011

i know i do the same crap cuz i'm too lazy. i dont like taking off more than I have to lol glad you fixed the problem

**thewaitinggame** · 08-29-2011

lol yeah, and to top off that day after being annoyed on how long a simple fix should have been, we took my car to the store later that night and was maybe gone for a half hour. We were going to drop off groceries at the house and go back out to get something to eat and my wfie say, you're car is leaking something. So I get out and a trail of coolant coming up my driveway. Pop the hood and I noticed that I didnt tighten the hose clamp on the lower radiator hose. I double checked everything but that I guess. All the other clamps are still the stock pinch clamp but on the bottom I have the ones that you you tighten with a screwdriver or socket. We look down the street and see a trail of coolant. So now off to the store to buy new coolant (in her car of course) but as we left I noticed the hose popped off only about 5 house down the street. I was very lucky it stayed on that long. Just a bad day.

One more question though, after I changed that earlier in the day and started up my car in the driveway and later when I drove it, I noticed the temp rises my quicker that it has been in the past. So I'm wondering if my old parts were bad for a while and didnt show the correct temp? This morning on my was to work it got to 210 within a few miles of driving on the freeway, its low 60s in the morning too. Before I changed the sensor and thermostat I could make it all the way to work and it might read 210 but on a cool morning maybe not. Its a 30 min ride to work too. My car have been like that for the past few years for sure so I dont remember if it used to rise that fast. Does that sound normal? or does it sound like I have a defective new parts. I did bleed the system once and have had to top off the coolant twice so far, would air in the system cause and weirdness?

**bps02gtp** · 08-29-2011

its possible there is a small amount of air in the system. also with your mileage its poosible that the new thermostat is not the first new thermostat. which temp did you get? if you get the 195 ur gonna see it at 210. you mightve had the 180 temp thermostat in there before you put this new one in.

**thewaitinggame** · 08-29-2011

ok I will try to bleed the system again and yeah I did get a 195 thermostat. Its just weird that it goes up to 210 so fast, i mean in under 5 minutes, doesn't seem right. I guess if there is still air in the system it might do that. It also hovers a half line above 210 and when it hotter it goes to the line above 210. Its just freaking me out because before I did this it wouldn't hover around constantly that high and heat up so fast. But like you said maybe it was a 180 in there before. Guess I will keep my eye on it and keep checking it for a while. Thanks again

**bps02gtp** · 08-30-2011

Yea with a 195 it'll def do that. But if its getting to be at the line above 210 that's way to hot that's like 230. Hopefully u just have air in ur system

**thewaitinggame** · 08-30-2011

yeah i hope so too. The last 2 time I drove it and checked the coolant it was a little low and im sure its because its working through the system as I basically had to do a complete fill after I losted most of my coolant. I bled it again today so I hope a few more checks and it is back to normal. I never had a problem before I did this, no coolant leak, coolant in the oil and everything looks good so far as far as that goes. I hear air in the system is hard to get out so I will keep trying. I wonder if for some reason the gauge isnt reading correct now. I can watch the needle rise within a few minutes of driving and what else is weird, after my car sits for even 3-4 hours and i start it, the needle reads 170-175ish. Oh and I did look at my old thermostat and it was a 195 so I dont get the total change with this with using the same degree temp stat.

**bps02gtp** · 08-30-2011

i dont think you'd be able to tell by looking at it. theres not much of a difference. i'm pretty sure that you had the 180 in there and just didnt know it. all you have to do as far as bleeding the air out of your system is make sure all the caps are closed, let the car get to its operating temperature, and then loosen the little bleeder screw on top of the termostat housing. once all the air is out you'll get a constant coolant flow. tighten it up and then if you want loosen it again just to check and the second you loosen it you should get coolant coming out. and the engines get hot quick and they stay hot. if you look at almost any car the temp guages first number posted is 100 but in the grand prix's its 160. i know my trucks themp guage reads 100 and its a V8 5.7L. takes longer to get warmed up than the grand prix does.

**thewaitinggame** · 08-31-2011

ok, i think everything you're saying and what I'm seeing seems like everything is fine. Oh and the temp doesn't go to the 230 it just goes up to the first short line above 210, so maybe 215? So I guess that's normal. I still have my old thermostat and I saw a 195 stamped on it so I assumed that it was rated for 195. So if it was maybe it was going bad and that's why I'm noticing a change with the new one in. And with the bleeding, that's what mine does so I'm sure that's fine too. Thanks bps02gtp for replying so much, it really helped out!