Ok, so I replaced both the radiator fan motors in my car cause I realized they weren't turning on and my car was overheating, and when I tried to liven the wires they still wouldn't kick on. So after I replaced them, only one turns on now. The other turns on if i liven its wire, but thats it. I swapped the relay with another one and still the same problem. Does anyone have any advice, or, does anyone know if it would be safe or smart to just cut the wire on the fan that doesn't work and splice it into the wire on the one that does?

 

What are you defining as "overheating"?

Reason I ask that is, about 99.999% of the time when people on this board post this question, it's because they have some kind of idea of what constitutes the "correct" operating temp, different from the factory's. Not "wrong" necessarily, just at odds with the factory's design.

 

It doesn't overheat anymore. And by overheating, I mean the temperature would climb if I sat in traffic until it hit about 240 deg and I got scared and pulled over. Now that the 1 fan kicks on, it will sit at about 180 deg.

 

That's exactly what I mean.

That is NOT overheating. That's what it's supposed to do.

The factory "gauge" isn't very accurate to begin with. Let's go out on a limb, and assume that it's unusually acuurate for one of those trim option things, and let's say it's only 10 degrees off.

The fan switch in one of these cars TURNS THE FAN ON at 234 degrees. That means, as far as the factory is concerned, the engine DOES NOT NEED COOLING AT ALL until it reaches 234 degrees.

Notice, that 234 degrees is easily within 10 degrees of your "240 degrees" observation on the "gauge" (I believe that's what people call that pretty thing in the dash with the cute little hand that waves around next to the cartoon of a thermometer floating in water...). Sounds to me like everything about your car is probably working exactly right.

If you take distilled (pure) water at sea level pressure, it boils at 212 degrees. We all know that. But that's only the BEGINNING of understanding. If you add 30% antifreeze by volume, that boiling point AT SEA LEVEL PRESSURE goes up to around 230 degrees. If you put that under the amount of pressure that a radiator cap does, about 16 psi, then the boiling point goes up to 265 degrees or so.

I'm guessing that most people's fear of "overheating" is based on their "knowledge" that water boils at 212 degrees. While that's entirely correct, all by itself, it ignores the realities of physics; which is, that a solution of almost anything in the water will raise its boiling point, and that increasing the pressure raises the boiling point.

Personally, I would not go hacking on my car's wiring in such a critical area, without first understanding what's going on.

One of these cars with a properly operating stock cooling system, if allowed to sit still and run, the temp will slowly climb until it reaches 234 degrees or so, basically the "gauge" will just be touching the red (the fan temp switch isn't really any more precise than the "gauge"); the fan will kick on; the temp wil gradually drop to around 210 degrees on the "gauge"; the fan will shut off; and the temp will begin to climb again. This cycle will repeat itself about every 5 minutes or so. about 3-3.5 minutes of warming up and 1-1.5 minutes of fan to cool it back down. Mine will do that for hours, literally until it runs out of gas.

Bottom line:
Keep your cooling system full of coolant and leak-free; use a mix of 70-30 water to AF, or thereabouts; keep a good radiator cap installed; and don't worry about the "gauge" touching the red when it sits idling in traffic, as long as the fan kicks on at about that time. And above all, DON'T hack into the wiring to "fix" something that isn't broken.

 

when I bought my camaro, I didnt know it turned the fan on at 230, so I assumed that the fans didnt work, but it never overheated. Finally after a hard long drive, they turned on lol, i was relieved. GM did it for emissions purposes. Ford doesnt do that. Vettes sit at 220 all day long. I like my honda accord, it sits at the same exact temp all day long, under any condition. I'll be getting a DC controller for the maro pretty soon

 

The two fans work independently of eachother and under different control systems. Have a look at the tech article about "ultimate fan control" in the tech articles of this website. Although the article is focused on how to modify/improve over stock it also gives an excellent description of how the stock fan systems work. There's a lot more to it than you think!

 

yea but its just messed up when your use to never seeing your car go over the 200 marker then all of a sudden it does. Its worth testing the fan, temp control sensor, relay or broken wires. I'm not saying imediantly go out and start cutting up the cooling system but its worth checking out before you go out for a long drive and find out some pos sensor relay or wire was grounding out or shorting out the hardway.

Check this out

https://www.thirdgen.org/techbb2/sho...hreadid=324280

 

This is the closest that I could find

https://www.thirdgen.org/newdesign/tech/cool.shtml

 

But the fans never went on, and it was only like 10 degrees below the "red" zone. Now one of the fans kicks on well before 200 degrees. Does this mean that I have an aftermarket computer or something? I tried switching the fan relays, and the same thing happened, only the passengers side fan kicked on. Also, I changed my oil after I fixed the fan problem and the old oil had a terrible burnt smell to it. I'll read the listed articles now before I go on further though.

Ok, I read the articles, so the car must have had an aftermarket switch installed then? Anyways, thanks for the information everyone, at least my cars not the wiring nightmare I was dreading it would be.

 

Redbird- yeah, that's the one. I think it used to have a different title but that's the article.

 

you might have installed an aftermarket switch or the calibration on your guage might jsut be off.. If it redlines then worry.. My engine used to run at 250 all the time.. Then the fan kicked in.. Did you do the ab connector test I said?

 

My 84 Z28 w/350 running mechanical fan and stock rad always sits @ 120*c/250*f never above and never lower once its all warmed up.

As for only one fan coming on, its supposed to do that. The fans operate on 2 different temp sending units and are set to turn on at different temps.

 

Well, not sure about it hitting 240 or anything, but... On my 91 TA, the gauge will hit the first notch above 220 and the first fan will turn on and drop it back down again. If your stock system was letting it get well above that particular notch, you definately had/have problems. The only time it ever went above that notch was when the water pump was read its last rites while I was driving down the road and it went into overdrive getting up to 260 as fast as possible. You should have 2 fan switches, one controlled by the ecm and the other controlled by temperature. The secondary fan will come on supposedly around 240 or so and I think always comes on when the AC is on.

My thoughts are these, GM may have meant well, but letting a car hit 230-240 before a fan turns on does NOT leave a lot of room to play with if a fan dies, water pump/radiator/hoses/etc go on you.

What I suggest and what I am getting ready to do, myself, is buy a 180 thermostat and a replacement fan switch for the secondary fan that will turn it on at say 200 and off at 180 or 185. This will now make the secondary fan the primary/first fan to turn on and the other fan will now become the backup/secondary turning on at 230 or whatever temp the ecm is set at. The new primary fan will still be controlled by temperature and the old primary/new secondary will still be controlled by the ecm, just the new primary will have a lower temp setting instead of that godawful 240+ setting it has now. I live in Fort Lauderdale and I sure don't need that thing running at those horrendous temperatures. I think I have all that right, still reading up on changing the switches and such.