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Hi all, I have a 2012 with 125k miles. Last week while stuck in traffic, after hour and half commute, I got a warning message that engine is hot and to stop safely. I turned on the heat at max level which cooled off the car and I made it home ok. I topped off the coolant which really wasn't low and decided to keep an eye on it. Last night, the same thing happened again so I'm now trying to diagnose the problem. I don't see any leaks but there is a slight smell of antifreeze when the car is overheating.

I started the car in the driveway and rev'd engine till the car wamed up and I got it to overheat again. I noticed that the cooling fan would only run for abut 3-4 seconds and stop again. It would only come on again after a couple of minutes of being off.

I turned on AC at max level expecting fan to run longer but it again only ran for 3-4 seconds. It did however turn on more frequently.

During both tests, I get the feeling that the fan isn't running at full speed. I now suspect that the fan contoller module may have gone bad but I'm not sure. It seems like the fan runs much faster when I hot-wire it directly to the battery.

Any ideas before I spend the $$ on a fan assembly because I can't buy the fan controller module separately.

I appreciate your thoughts.
 

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Most repair questions end up here for the most looks. I'm afraid few to date have done many repairs on the '12+ models.

Fan control module as part of the fan assembly sounds a bit odd, prev. years only had a resistor pack in that area for two different speeds when commanded on by separate relays. How did you bypass that to wire fans directly?
 

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Wiring to fan motor WILL increase speed and normal, the low fan power goes through a resistor somewhere to slow fan down. Sounds like your low fan circuit has an issue. They need to be running solid when the motor is overheating. 3-4 seconds don't cut it there.
 

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It does seem that your troubleshooting points to the module. I would open it and see if there is anything repairable in it...nothing to lose there. These are available on eBay for about $50.
 

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The old Tempos when first went to EFI had those type modules and pretty easy back then to just physically drop them entirely and rewire around to make a fan setup that was bulletproof. Maybe not now though, the electronics have gotten too intertwined into everything now. PCMs want to read everything and any custom change you make generally results in a dtc for something.

I see rivets and easy to get into, like FocusKnot I would be delving deeper into that module, but just the way I am..............could be something as stupid as an internal mini-relay, I circumvented $200 IRCM and CCRM modules on Fords by adding a $5 relay externally patched into those boxes to get back a/c when the internal ones failed. You could not get the modules at the time, Ford was selling every one they had as they were causing so much trouble. 1 year wait I was told when trying to order at dealership. The fix I did is still working now some 15 years later.

FYI, the fans generally WON'T run at full speed unless a/c commands them to do so, they normally run on low or maybe 2/3 of full speed and that is enough for most conditions. High is for overheat or high load a/c, the control device knows when to switch. You're looking to get that slightly lower speed working when commanded to, the 3-4 seconds is an error, like a relay pulling on then dropping off because shorted or burned up. You seem to have the 'on' command but it's not staying on. That may be easy to fix.
 

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I see rivets and easy to get into, like FocusKnot I would be delving deeper into that module, but just the way I am.............
Yeah, I would like to get my hands on one just to tear it apart. It is likely solid state and may be potted. I would still get into it and make a schematic of its innards.

Actually those are Torx screws but it is hard to tell from the photo. Here is a closeup view...
 

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Discussion Starter #7
Thanks for the replies. Today, I asked a coworker also with a 2012 Focus to run their AC on max so I could compare the fan on/off cycle and speed. Their fan came on for about 18-20 seconds and would only be off for about 5 seconds before coming on again. Mine would only come on for about 5 seconds and would be off for much longer (guessing about a minute). Speed seemed similar. I guess that supports a faulty fan controller module theory???

Thanks for the eBay suggestion FocusKnot but I'm worried about not knowing the reliability of what I'm buying. I reluctantly ordered the replacement fan assembly from Ford and will try to install in the next couple of weeks. Before I install it though I'll open up the old module to take a look inside. In the mean time, I'll be watching the temp gage closely.

Thanks again for the help.
 

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Mine would only come on for about 5 seconds and would be off for much longer (guessing about a minute). Speed seemed similar. I guess that supports a faulty fan controller module theory???
I'm thinking it is a solid state module and it is shutting itself off due to internal heat. Cools down...comes back on...shuts off, and so on. That's why I would like to know what is in that box.

I don't blame you for wanting to buy a new one vs eBay, but I suspect Ford has created another failure item here given all the Internet posts I found about it.....and the reliability of new vs used is probably about the same.....bad.
 

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Oh ho, SURELY they wouldn't do that would they???? LOL. Why I've bought my last Ford ever and sick of that crap which has only intensified over the last 20 years. When you buy two of the same car it sticks out like a sore thumb, all the changes they do to LOWER the quality of things to break earlier.

Hey, per post #7 and the supposedly correct running '12 model, do you reckon they have gone to cycling the fans on and off to match a/c compressor cycling? That would be a new one on me and would tend to burn out fan controls much faster with all the power spiking going on there.
 

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Discussion Starter #10
Hey amc49. For the correct running '12, I didn't pay attention to the sound of the compressor kicking on/off but it seemed to me that it was not on the same timing.
 

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All I can say not having one of the later models is that when engine is around overheat territory running the fans for only seconds at a time won't cut it, you need good solid running in there for a solid bit to bring temp back down. Nothing else the car can do will replace that other than shut engine off.
 

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Discussion Starter #12
Today I replaced electric radiator fan assembly including the fan module. After installing, the fan came on with the AC and when the engine temp started to climb. So I think this solves it.

I did open the old electric fan module but didn't see anything wrong such as broken solder joints or discolored components. I did notice that the old fan didn't free-spin quite as easy as the new one. But only slightly. So, it could be that the old fan messed up the old fan module.
 

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I didn't read the whole thread but I was wondering if you were paying attention to the coolant. If its not leaking externally..... Well..
 
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