Taken from your photo.

This switch under your upper rad hose at the front of your intake manifold looks for all the world like a temp switch for your electric fans. Remove the wire from the switch and with your key on touch that connector firmly to ground. Your fans should run. If they do. That switch is bad. If they don't. Follow that wire back to a relay mounted somewhere. It will be a 4 wire relay. One wire will be hot all the time. One wire will go to the fans. The wire from this switch of course and the 4th wire will have power with the key on.
Check all of this and get back to us.

 

And then, maybe not. Looking closer yet at your photos.

That red wire from that temp sensor is spliced into this green wire at the alternator harness. The green wire is the factory temp wire for your guage in the center cluster. Thought I was onto something, maybe not. Keep looking for another temp sensor.

 

That's why I asked for more photos. Isn't the temp sensor in the drivers side head, not the intake?

It wouldn't surprise me if those fans are wired to run continuously, but have failed, or blown a fuse.

More pics please! And consider eliminating that fuel filter and rubber hose.

 

Once you get your fans sorted, I think you will find them to be wholly inadequate. Look at how much area of the rad those fans are pulling through. Not much, maybe half at best? Here’s where a proper shroud comes into play. It allows small fans to create a negative pressure across the whole of the radiator.
But, no so fast with electric fans: the shroud has to be able to bypass some of the air around the small fans since at highway speed, the air being shoved thru the radiator is more than can pass thru the fans. This is why you see those little flaps on some factory electric fan shrouds.

But none of this means squat if you have those gaps open around the rad. That allows a ton of air to bypass the radiator entirely. C3 Vettes, with the rad laid so far back and small nose openings, need lots of help guiding the air into the rad compared to say a Chevelle. Close those gaps!
Also make sure you have a proper factory air dam under the nose to kick the air up to the rad.

 

The OP did say he had a 327... the temp sender is located on the forward part of the intake on 327s and 427s. Didn't move to the head until the 350/454s came out.

 

The lower radiator hose has a spring in it, squeeze its entire length . it should be there for 80 % and centered, if 2 or 3 inches on either end dont have the spring it shouldnt be enough hose to collapse


The fans should come on at preset temps for your controller. Most come on at 190* and the second at 200* or somewhere close to that. Mine are programmable so mine are 185/195 I believe. If they turn on with just the temp switch in a head they are ground controlled and are both coming on at the same time probably They should have power all the time and the temperature sensor is a switch that just give the fan ground. YOu can test both fans with the car ignition on but not running by connecting the negative fan wire to ground. Follow the wiring and you should find a controller that has relays on it for them to turn on. They should also be fused so you may just have a blown fuse somewhere depending on how they are connected.

driving around at 45 mph should be more than enough speed for air flow to cool the engine. Stop and go is what makes you rely on the fan. IF you can get on a road with no traffic and do 45mph you should see stable temps. If you do not you have an air flow and coolant flow issue. Air flow would be air not making it through the radiator and going around it and or coolant not flowing through the radiator enough with your hood up you should be able to see in front of the radiator and that is your air box. Air comes in from the grill a little and mostly from under neath in front of the spoiler. If you do not have a large spoiler then that is a major issue as well.

As for the fans, measure them, if they are 12 inch they are fine, 10 inch may be kind of small depending on the horsepower rating...

the shoud is another animal all together. Let us know if your fans have power, where the wires lead to, take pics and let us know if you can get them to turn on manually. If all that works out we can work on the shroud issue then

 

I honestly don't know. I noticed a probe going into the radiator. You can see it on the upper right hand corner of the picture i posted. I believe that is running straight to the battery, so it should turn on when the car turns on?

 

Now that you mention it, I do belive there is a little box that has wires connected to it from the radiator. I was wondering what that was and it did have a fuse in it.

So in my case, the thermostat on the intake manifold doesn't control when the radiator turns on?

 

What's at the other end of the probe wire?

Please post photos!

 

Ya know after I bought it, the car did have white foam around the radiator, I was like WTF? So I took them out, guess that was a bad idea. I will put new ones in and check to make sure there is a factor air dam under the nose. Live and learn.

 

I will take pictures when I get home.

 

I did squeeze it and did feel something in there. So I guess that's good.

 

Will do, but it that sensor is right next to the radiator hose, could that mean that it works off of the thermostat? I always thought the thermostat would tell the fans when to turn on.

 

thank you everyone for all your input. It's invaluable. Keep it coming!

 

In your house it does. In a car, a thermostat is just a valve that opens when it gets hot (when it works) to let coolant flow. It can't tell anything to anyone.

 

Progress!!
the probe in the radiator is the temp sender to the fan controller. Yes the box it goes to is controlling your fans, make sure there is power going in.

good news that the lower hose has a spring in it

the foam was there to force air through the fan, yes replace it until you can get a better looking solution.

the sensor in the intake is for temp gauge inside the car

 

will do. Thank you. I will report back.

 

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This guy is a scammer, ignore him or block him....hopefully he will contract a severe case of Syphilis and stop bother us

 

Two things to comment on -
1. huge air gap all around the aftermarket radiator. This needs to be sealed to the radiator mounting frame (as does the base of the hood) so that all cooling air 'only' passes through the radiator core.
2. electric fans - perhaps less of an issue with a small block - but differences of opinion as to whether your type of set-up is better than an OEM viscous fan and shroud. Jury's probably split 50/50 on this untill the engine becomes a big block......then the differences of opinion 'kick-in'!