Cooling fan issues

[Shortbus Commando]

Hey guys, I got a weird one that I need some help with. I've got a 2011 Taurus SHO, and my fans were running non-stop, so I started with the cylinder head temp sensor, then went to change the cooling fan relay (once I finally found it). The new one I put in was working correctly at first, turned on and off when I started/stopped the car, but on my first test drive it stopped working. I got the car home and hooked my diag up to it to see what was going on. When I tested the relay on the car, if I put in a fan speed request below 90% it would run, but when I maxed it out at 93.99% (as it would be when it gets hot) it would shut off. If I turned down the request it would turn back on. My question is, do you guys think this is just a bad relay, or do I need to calibrate it to the car somehow?

 

[Shortbus Commando]

So I bought another relay to verify that the one I had bought previously was working, due to it only not working at max speed, and it did the same thing, so I don't think it's the relay. I have voltage to the relay of 12.4v, and at 0% I have 3.54v. When I step up the speed % it seems to drop the signal voltage accordingly. This is what I've seen for the signal voltages;
0%-3.54v
10%-3.17v
20%-2.80v
30%-2.46v
40%-2.11v
50%-1.75v
60%-1.39v
70%-1.05v
80%-0.69v
90%-0.34v
93.99%-0.20
Anything below 90% and fans will turn on, but will not stay running when I max it out to 93.99%. I get the same results whether I'm using the block as ground, or the common for the main power. Is there another fan control module that I should be looking at, or just the relay?

 

[Shortbus Commando]

One other thought; I did buy a cheap relay. Is this one of those things that you have to buy OEM for it to work correctly?

 

[Shortbus Commando]

So update. I did get it working again (so far anyways), and it looks like it was the cheap Chinese fan controller was the problem. I wasn't getting anywhere with it, so I took apart the original and one of the cheap ones to see what difference there was. It is definitely a case of you get what you pay for in this instance. The components looked very flimsy, the capacitors (plural in this case, versus one on the original) were smaller each, and the circuit board was not only larger, but you could tell the components were inferior. I ended up getting the Gates FCM128 control module, and so far it is working great. My a/c even feels colder.
Now I know everyone will probably roll their eyes and say "duh, you never use cheap parts", but lets be real here guys; I've used plenty of Chinese parts that have worked fine over the years, (most of the parts are produced there anyways, whether you want to believe it or not), but in this case, don't skimp when it comes to electronics. This will be a lesson learned for me; sometimes you have to pay for quality.

 

[c man]

So I bought another relay to verify that the one I had bought previously was working, due to it only not working at max speed, and it did the same thing, so I don't think it's the relay. I have voltage to the relay of 12.4v, and at 0% I have 3.54v. When I step up the speed % it seems to drop the signal voltage accordingly. This is what I've seen for the signal voltages;
0%-3.54v
10%-3.17v
20%-2.80v
30%-2.46v
40%-2.11v
50%-1.75v
60%-1.39v
70%-1.05v
80%-0.69v
90%-0.34v
93.99%-0.20
Anything below 90% and fans will turn on, but will not stay running when I max it out to 93.99%. I get the same results whether I'm using the block as ground, or the common for the main power. Is there another fan control module that I should be looking at, or just the relay?

I used to have the same issues with my cooling system until I finally ended up trading it in.
Mine was a 2011 as well. Is yours WHITE by any chance? ;-)
Did your repair stay fixed? How's it runnin?

 

[Shortbus Commando]

It is white actually. It's been running fine since I used good OEM parts.

 

[c man]

LOL too funny!
I still got some spare parts for the 2010 - 2012 version, which is what I had and you have.
I bought them last year, when I was still planning to put em on the car.
All the tail lights - stock dealer parts in dealer boxes.
Interested?