Car overheating fans not kicking on

Good call on the sensor, I would get AC Delco. Next the fact the fan did not come on when you disconnect the sensor tells me there might be problem with the PCM fan signal driver.

Try the sensor first then replace the PCM with a used one, its plug and play. Here is the location.

Check out the diagrams (below). Please run some tests and get back to us.

Cheers, Ken

My cooling fans will not turn on even when it is 220 or more degrees while running but they do work when hooked up straight wired to the battery. So far I have changed the temperature sensor, thermostat, checked fluids, multi-meter tested the wires and relays still nothing has changed, the fans just will not come on. So instead I am going to be hooking the fans up to a toggle switch to make sure the fans come on so the car will not overheat while driving. Can anyone help me step by step with the procedure in properly wiring the fans to a toggle switch so nothing will be blown and or burn out? Where should I start? What wires am I looking for and what colors? The toggle switch is a three prong switch one is for the 12 volts one for the load and one for the ground please anyone help!

Using a toggle switch to do that will set codes in the system and turn on the CEL. If all of the external parts are working then the PCM is not turning the fans on.

Did you test using the jumper wires as I put in the earlier posts? Did they turn on/off with the jumper wires? If not then you still have a problem in the wiring or a bad relay. Just because they click does not mean they work.

If there is one problem it is another with this car, so I will start from the beginning. I replaced the bulbs in my cluster with LED's and added a back face panel to go over the gauges. I had to take the needles off to do so. I placed the needles back on to what seemed cores took some adjusting because I forgot to mark them before I removed them and my gas gauge does not move anymore. Could be a ground issue or the gauge itself? Some said because seems my float is working (I sent a video texting it with a multi meter), so instead I bought a aftermarket gas gauge hooked it up to the wires connected to the original wired to the fuel pump and float, purple for the sender wire, black for the ground and grey for the power 12 volts seems to work okay. I guess now the temperature gauge seems to be showing the car is overheating while driving I noticed the temperature needle moving into the middle line of the gauge. Usually it never even reaches that far. Then I noticed it went passed the half way mark as if it was overheating. My gas gauge seems to have dropped also because I have not driven that far. Is it a thermostat issue? Or what? Can anyone help please?
I am sending some pictures of how the gauge looks while I was driving for over thirty minutes.

Hi Genius, that is a bit on the hot side is it not. Have you seen what the temperature gauge displays when the radiator fan turns on? Or what the temperature gauge displays when the A/C is turned on? Not having a radiator fan work proper would make it run pretty hot. Did you notice if the fan was on when the temperature gauge displayed that hot? You have an ohmmeter? Need a measurement at the coolant sensor. It needs about 1400ohms for the temperature gauge to read cold. And then when its warmed up, the coolant sensors reads about 700ohms but if the temperature gauge displays hot temperature, then there is the problem. You could check that right away but radiator fan operation and real engine temperature is more important than what the temperature gauge displays. Let me know how it goes.

Well I replaced the thermostat does not seem like it helped at all. Coolant seems to be topped off good. Could use maybe a half a quart of oil. Here is a short video on what it is doing.

No video.

Have you seen the radiator fan do its job? If not, turn on A/C open the hood and take a look to see if radiator fan is running. If it is, turn off A/C, fan should stop. If it stays running, restart engine. Fan should not be running, let engine run until the fan turns on. Then take a look at temperature gauge, see where the needle is pointing. Usually it is about a bit over middle temperature. Then when the fan reduces temperature and turns off, take another look at temperature gauge. It is usually a bit under middle temperature. Now if the fan does not turn on with the A/C, that is probably the problem.

Sorry, I tried up loading the video. The fan cuts on when I turn the AC on but it did not seem to kick in when the car is just running and the temperature sensor seems to read hot.

And if you could borrow a scanner it can tell you if there is a sensor problem. Because you can see sensor voltage which would probably throw a code if it was bad anyway . But when you see the sensor is normal and the gauge showing hot then well you know. Can measure sensor with ohmmeter it is in the other post. Is it really getting that hot though? When it is parked and you let it idle, does it get as hot as the pictures you sent show? And no fan?

Well in a video I tried to send the engine was hot but not scalding enough for me to touch it. I tested the sensor with a multi-meter, seemed to have jumped around before I started to read, but I possibly had the polarity wrong while trying to get a reading. I will see if I can send the video's again.

Let me know if the video works now.

No video.
Have YouTube? Leave a link?
When the car is cold and the key is off, where is the temperature gauge needle? It is a bit below 160 right? Then when you turn the key on, the needle moves to 160 right? Or does it move a bit above 160? Then, when you start it, about how long does it take to get to 210?

Okay, I will post a link. Well it takes about five minutes to get to the middle point on the needle then keeps moving up, key off it drops down a little the on start moves right back.

Have you had a chance to make a video? Be sure to make it from full cold.
That needle start at 160?

Well it starts from the starting point of the needle like normal then after about five minutes it seems to go all the way up to the half way mark on the needle.

Can you view the video now? I converted it.

Video 1.

Sorry for some reason it only lets let upload 43 seconds of the video.

I uploaded the videos to YouTube. Here is my link to the first video, sorry for the trouble.

https://www.youtube.com/watch?v=6TMR0RMYQy4&feature=youtu.be

Here is the temperature sensor test video link:

https://youtu.be/Rsv2jqnIq48

https://www.youtube.com/edit?o=U&video_id=6TMR0RMYQy4

Sorry I am new to uploading YouTube videos. Okay here is the real link to video number one:

https://youtu.be/E3UBtKchljE

It is no trouble at all.
I saw that video and the way that needle jumps up makes me think it is not running hot. It is an electrical problem. A bad temperature gauge or sensor. Does it have a check engine light that is stuck on too? If so, you should definitely have it scanned for code numbers. Even if the check engine light is not on, that coolant sensor should be checked with a scanner or an ohmmeter. It is probably a bad sensor, but I could not recommend replacing it without scanning or measuring it with an ohmmeter first. https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

No check engine light on at all, but I will run a scan on on the vehicle to check for any codes. I will replace the gauge I have another cluster laying around somewhere and I will replace the temperature sensor and see if anything changes and let you know the results.

Since you have a scanner you can see temperature data and temperature gauge at the same time.
So when the data reads normal and the gauge jumps up. Retest with another temperature gauge.

The scanner is just a basic ob2 scanner can I still test it?

Well if it only shows codes then yes you can test it. But they also have an option where it shows data and that will show exact temperature.

Got it. I will update you on the results. Thanks!

You say you removed the needles and added an overlay to the dash and after that this started correct? I would say the issue is the stepper motors are failing and the cluster needs to be repaired. Very common in that vintage to have the stepper motors fail, especially if they were touched at all. There are kit's and places you can send the cluster to for repairs. I do not recommend DIY unless you are very skilled at circuit board repair as the boards are not very rugged and unless you are extremely careful you can damage the board itself.

Thanks.

Just do not want to see you chasing overheating or other issues if it is a bad reading on the cluster.

Yes, but but the temperature gauge was working fine before and I believe it still is so far. I have replaced the temperature sensor and thermostat and temperature gauge still reads hot advertising it for about five to minutes my fans are not kicking on unless I turn on the AC. I ran the wires from the fans to the battery and they cut on, swapped the relay with my fog light relay and nothing changed. I am just so frustrated with this car now.

That is the issue, if the stepper is failing it could read wrong. With the fuel stepper being bad it is a real possibility. When you shut the car off and then turn the key on, where does the needle set? Does your scan tool read live data? If so compare it to the gauge.

The needle actually does not move at all for the gas gauge.

How about for the temperature gauge?

The temperature gauge starts off in the cold mark until about five or six blocks of driving the car. The temperature gauge needle jumps up to the halfway mark indicating it is beginning to overheat. The fans does not kick on even reaching 260 degree mark but I wired the fans to the battery and they immediately came on so they do work.
so far I have replaced the thermostat, and replaced the coolant temperature sensor, but it is not the ACdelco OEM. Would that make a big difference?

If it is not smoothly rising from the low mark as it warms up you have a bad stepper motor or a bad head gasket. The coolant is not going to suddenly heat up and cause the gauge to jump. A bad thermostat would cause it to simply either heat up rapidly until it boils over or if it fails open it will slowly heat up and probably set a code because it does not reach the control temperature in a short time.

It does raise up slowly as far as the temperature gauge as normal within time not rapidly it just keeps going tho never cools down.

Does it actually overheat to the point it boils out coolant? Or is it only the gauge? How about using an IR thermometer to check the temperatures at the block and hoses. That would tell you if it's real or related to wiring/cluster/sensor. The #93984 that HF sells is accurate enough for that testing.

Yes, it gets hot enough that is boils the coolant.
And what is "HF"?