Sponsored

Radiator Fan Issue

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
Couple days ago I have been experiencing issues with the Radiator fan ramping up to 100% RPM upon using the remote start and manually starting the car. The temperatures outside are around 40 degrees with that being the warmest it gets. I've turned all A/C and heating settings off and the fans will still remain at 100% even after driving. Cars not overheating at all and the thermostat opens fully when needed.

Maybe an A/C clutch cycle switch?

Any help would be appreciated.

2016 V6 Mustang Convertible @ 50k Miles
Sponsored

 
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
Gonna bump this.. Been diagnosing like crazy and still can't figure it out.
 

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
102
Messages
10,360
Reaction score
8,495
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
I noticed mine did the same thing the other day. On start up I went to close my garage door and heard the fans at 100%. I drove to my destination and the fans were still screaming. This happened several times. Each time I did notice the heat settings had the defroster turned on. This turned on even after I turned off. I turned it off shut off the car went and did my thing and upon re-starting the car the defroster was on. It did this 4 or 5 times then quit.

Turning off the defroster did not shut off the fans when I tried that.

I thought I had them turned on in the tune but did not.

Hasn't done it since.
 
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
I noticed mine did the same thing the other day. On start up I went to close my garage door and heard the fans at 100%. I drove to my destination and the fans were still screaming. This happened several times. Each time I did notice the heat settings had the defroster turned on. This turned on even after I turned off. I turned it off shut off the car went and did my thing and upon re-starting the car the defroster was on. It did this 4 or 5 times then quit.

Turning off the defroster did not shut off the fans when I tried that.

I thought I had them turned on in the tune but did not.

Hasn't done it since.
Yeah pretty much the same issue, when the A/C compressor clutch is engaged the fans are supposed to turn on that normal. However, my car doesn't turn them off even when the A/C clutch is disengaged. This is what led me to think its the A/C Clutch cycle switch, I ordered the part for $30 going to see if that fixes the issue.
 

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
102
Messages
10,360
Reaction score
8,495
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,

Sponsored

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
102
Messages
10,360
Reaction score
8,495
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
Mine did it again today. I unplugged the high pressure switch and the fans shut off. So I am assuming it is stuck.

Not sure if this is the same as what you are calling a cycle switch.

To add insult to injury when I turned on the AC the compressor turned real slow then stopped and smoke came out of the clutch.

My drivers door window motor went out last week.

Happy holidays to me.
 
Last edited:
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
Mine did it again today. I unplugged the high pressure switch and the fans shut off. So I am assuming it is stuck.

Not sure if this is the same as what you are calling a cycle switch.

To add insult to injury when I turned on the AC the compressor turned real slow then stopped and smoke came out of the clutch.

My drivers door window motor went out last week.

Happy holidays to me.
Yeah its the same thing, you're right with the "high-pressure" part. Its a pressure sensor that detects pressure in the A/C system when the clutch is engaged versus when the clutch is disengaged. Thus turning the fans on or off. I ordered the part waiting for it to arrive.
 
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
Mine did it again today. I unplugged the high pressure switch and the fans shut off. So I am assuming it is stuck.

Not sure if this is the same as what you are calling a cycle switch.

To add insult to injury when I turned on the AC the compressor turned real slow then stopped and smoke came out of the clutch.

My drivers door window motor went out last week.

Happy holidays to me.
Alright, replaced the pressure switch and it didn't fix it. Next step is trying to get a more advanced scan tool to look into it if that doesn't work, a ford dealer.
 
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
Final Update: This is a PSA to anyone with this issue. Connected a scan tool and physical A/C gauges and found that the low side pressure was magically at 350 PSI in 40 degree weather. Did a full A/C system drain, vacuum and recharge which fixed the issue. DO this before your compressor goes bad.
 

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
102
Messages
10,360
Reaction score
8,495
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
Any idea why the pressures went out of whack?
 

Sponsored
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
Any idea why the pressures went out of whack?
See this is where I get stuck, can't figure out why. My assumption is that when I got my car used maybe they overcharged the system? Could also be a condenser issue but I checked and everything was clean.
 

Brian_S550

Well-Known Member
Joined
Mar 1, 2018
Threads
7
Messages
527
Reaction score
702
Location
Chicago suburbs, IL
First Name
See username
Vehicle(s)
2015 Mustang 3.7L, 2016 Explorer 3.5L
Final Update: This is a PSA to anyone with this issue. Connected a scan tool and physical A/C gauges and found that the low side pressure was magically at 350 PSI in 40 degree weather. Did a full A/C system drain, vacuum and recharge which fixed the issue. DO this before your compressor goes bad.
Good to know, my convertible‘s radiator fans started doing this yesterday morning.
 

Basspro302

Well-Known Member
Joined
Apr 13, 2021
Threads
9
Messages
282
Reaction score
162
Location
Ohio
Vehicle(s)
2019 mustang gt
Final Update: This is a PSA to anyone with this issue. Connected a scan tool and physical A/C gauges and found that the low side pressure was magically at 350 PSI in 40 degree weather. Did a full A/C system drain, vacuum and recharge which fixed the issue. DO this before your compressor goes bad.
The low side was at 350?? What was the high side at?
 
OP
OP
Ninpop9

Ninpop9

Well-Known Member
Joined
Jan 23, 2021
Threads
11
Messages
90
Reaction score
83
Location
Illinois
Vehicle(s)
2016 Ford Mustang
The low side was at 350?? What was the high side at?
120-150 PSI. My theory is a valve inside the A/C system popped loose and was stuck causing the pressures to go out of wack and when the vacuum was placed on the system to recharge it popped it back into place fixing the problem. Common ford issue I guess.
Sponsored

 
 




Top