HVAC Fan Ridiculousness

[tradle]

This topic has been addressed, but what I'm seeing I cannot reconcile. I have a 2015 Limited. A bit ago, the HVAC fan would randomly turn up to high and I could only turn it down by switching to auto after several minutes. Per suggestions on this forum and others, I swapped the fuse but there was no change in behavior. I swapped the HVAC blower motor resistor, but the behavior now is leading me to believe I have a different issue. The sound made by someone repeatedly pressing the fan happens repeatedly, but the fan speed does not change. The blower is working, but seems intermittent in its speed. Anyone have a suggestion for what might be happening? I really don't want to take it to the shop unless absolutely necessary.

 

[peterk9]

Welcome to the Forum.
I don't know what is going on but it would seem that the fan is receiving a signal to increase its speed. I usually always have my HVAC system set to Auto and it increases/decreases the speed to maintain the set temperature. Perhaps you have a faulty blower control module.

Peter

 

[tradle]

Welcome to the Forum.
I don't know what is going on but it would seem that the fan is receiving a signal to increase its speed. I usually always have my HVAC system set to Auto and it increases/decreases the speed to maintain the set temperature. Perhaps you have a faulty blower control module.

Peter

Thanks Peter - I just replaced the blower control module (the resistor). I'm not sure if this is a short somewhere in the wiring, a bad HVAC fan/fan motor or the unit I purchased is bad. Or - that something entirely else is wrong in combination with the part I added being somehow faulty. Dunno.

 

[tradle]

Thanks Peter - I just replaced the blower control module (the resistor). I'm not sure if this is a short somewhere in the wiring, a bad HVAC fan/fan motor or the unit I purchased is bad. Or - that something entirely else is wrong in combination with the part I added being somehow faulty. Dunno.

I've been googling a ton on this today and have arrived at a possibility for the source of the issue. Ford labels this either a "heater core control unit" or a HVAC climate control module. I am yet to find where this thing installs - are you familiar with this part? Motorcraft Ccm-26 Hvac A/c Control Module Unit For 2015 Ford Explorer$79.99eBayFree shipping

I found several posts from people describing literally the exact steps I've taken and the symptoms I am experiencing - but no resolution.

 

[Michael Blackburn]

Could also be your climate control panel shorting out the fan speed control buttons.

 

[tradle]

Could also be your climate control panel shorting out the fan speed control buttons.

That's my thought too, Michael. Do you by any chance have a picture or diagram showing where that component is? I have seen exploded diagrams with it present, but I only know it goes behind the main front console somewhere.

 

[peterk9]

I've been googling a ton on this today and have arrived at a possibility for the source of the issue. Ford labels this either a "heater core control unit" or a HVAC climate control module. I am yet to find where this thing installs - are you familiar with this part? Motorcraft Ccm-26 Hvac A/c Control Module Unit For 2015 Ford Explorer$79.99eBayFree shipping

I found several posts from people describing literally the exact steps I've taken and the symptoms I am experiencing - but no resolution.

I just checked that part FR5Z-19980-B on both the Ford parts and AutoNation sites and it says it is invalid or may be obsolete so it looks like it is no longer produced.

Peter

 

[peterk9]

I don't know if this diagram is of any help. C228A HVAC module?

Peter

 

[tradle]

I don't know if this diagram is of any help. C228A HVAC module?

View attachment 428345

Peter

That absolutely does, Peter - thank you!

 

[J_C]

That's my thought too, Michael. Do you by any chance have a picture or diagram showing where that component is? I have seen exploded diagrams with it present, but I only know it goes behind the main front console somewhere.

If it helps there's a 2014, wiring diagram and workshop manual, download linked in my sig below.

 

[Michael Blackburn]

I was thinking of the actual touchpanel that has the buttons on it. The flat touch sensitive panel has a reputation for doing crazy things.

 

[tradle]

I was thinking of the actual touchpanel that has the buttons on it. The flat touch sensitive panel has a reputation for doing crazy things.

I'm honestly leaving that as a last resort to replace. From what I've seen, testing it (the FCIM/FCDIM) rarely flags as an issue. Based on what I'm seeing after the blower motor controller replacement suggests the origination of the signal to it is likely to be the culprit. I am replacing both the blower motor and the HVAC controller module first. If the behavior persists, I'll have to replace that panel.

For reference, the behavior I am seeing currently is that the fan increase button repeatedly engages on its own, even if the climate system is off. The HVAC fan no longer works at all on any setting.

 

[tradle]

If it helps there's a 2014, wiring diagram and workshop manual, download linked in my sig below.

This is exactly what I needed - thank you!

 

[funwithbono]

This topic has been addressed, but what I'm seeing I cannot reconcile. I have a 2015 Limited. A bit ago, the HVAC fan would randomly turn up to high and I could only turn it down by switching to auto after several minutes. Per suggestions on this forum and others, I swapped the fuse but there was no change in behavior. I swapped the HVAC blower motor resistor, but the behavior now is leading me to believe I have a different issue. The sound made by someone repeatedly pressing the fan happens repeatedly, but the fan speed does not change. The blower is working, but seems intermittent in its speed. Anyone have a suggestion for what might be happening? I really don't want to take it to the shop unless absolutely necessary.

This might sound crazy but grab a can of compressed air (don’t buy from an auto parts store; it’s cheapest in the electronics sections or at Office Depot, Best Buy, etc) and spray it into the sensor port (see photo). It could be covered in dust; see if this solves your issue. I’ll just bet it does! Let us know!

 

[tradle]

This might sound crazy but grab a can of compressed air (don’t buy from an auto parts store; it’s cheapest in the electronics sections or at Office Depot, Best Buy, etc) and spray it into the sensor port (see photo). It could be covered in dust; see if this solves your issue. I’ll just bet it does! Let us know!

View attachment 428420 View attachment 428421

I’ll give it a go - absolutely. Thanks for the suggestion!

 

[J_C]

Be careful doing that, isn't there a little fan in there? On several products with little fans, I recall the instructions state not to blow compressed air in because it could damage the fan.

 

[funwithbono]

Be careful doing that, isn't there a little fan in there? On several products with little fans, I recall the instructions state not to blow compressed air in because it could damage the fan.

CANNED…not from a compressor…used for electronics/pc’s etc. I use it all the time for many, many applications. It’s designed intently for purposes like this! Here’s an example; but I get mine from GE Medical.

Falcon Dust-Off Electronics Compressed Gas Duster 10 oz (4 Pack) [New Improved Version] Amazon product ASIN B07QJY6MKD

 

[J_C]

^ ? I'm sure a can is gentler than a compressor set at normal PSI, but I'm also sure that canned air is not specifically designed to clean out fans. Some sources state that you should hold the fan blades motionless while spraying it. The thing is, I bet that motorcraft fan assembly, costs a heck of a lot more than a $10 computer/etc fan.

 

[funwithbono]

^ ? I'm sure a can is gentler than a compressor set at normal PSI, but I'm also sure that canned air is not specifically designed to clean out fans. Some sources state that you should hold the fan blades motionless while spraying it. The thing is, I bet that motorcraft fan assembly, costs a heck of a lot more than a $10 computer/etc fan.

I use it on electronic and micro cooling fans for multi-million dollar MRI’s and CT’s in the field. It’s common practice. I’ve used it on my explorer many times…and other vehicles as well. It’s for gentle dusting of circuits, fans, micro-chips, pwb’s etc

 

[tradle]

@funwithbono - looks like you may be right. I sprayed through that vent and the fan didn't attempt to come on by itself. Further, I put the old controller back in and my climate system appears to be working again. I'll wait a few days to make sure, and will likely still replace both the blower motor and blower motor controller, as the latter has some corrosion on it. Regardless, I'll keep all informed as this might have just saved me a couple hundred dollars in parts. Thank you!