Radiator Cooling Fans cycling on/off

[Nitroheli]

Have a 2013 Ford Explorer XLT. Drove through some flooded streets due to heavy rain.
Now when I turn the A/C on, the two electric fans on the condenser/radiator cycle on high for 15sec. turn off for 30sec and then repeat this cycle. This only occurs when the vehicle is going slow or stopped. I've swapped the high and low fan relays
and also tried pulling the #2 High Speed Relay. The A/C put's out ice cold air so the sys. pressures should be
fine, and the engine temp is always normal. Was reading somewhere maybe the pressure transducer might be the culprit. Need help with this, not sure what to do next.

 

[peterk9]

Welcome to the Forum.
I take it that this is a recent and new issue or can it be that it has always been that way and you only just now noticed this? I can't say that I've ever paid attention to the fans when the A/C is ON. You A/C is working well and how about the engine temp? Is it in the 'Normal' range as before?

Why does the radiator fan have to start when turning the A/C on?

The inner blower fan is the one that pushes the air and not the radiator fan.

mechanics.stackexchange.com

Peter

 

[Nitroheli]

Welcome to the Forum.
I take it that this is a recent and new issue or can it be that it has always been that way and you only just now noticed this? I can't say that I've ever paid attention to the fans when the A/C is ON. You A/C is working well and how about the engine temp? Is it in the 'Normal' range as before?

Why does the radiator fan have to start when turning the A/C on?

The inner blower fan is the one that pushes the air and not the radiator fan.

mechanics.stackexchange.com

Peter

Thanks for your reply Peter. Yes, this is a new issue that just started. I noticed it right away because both fans are running full blast, off, then on at 30sec. intervals and their very noisy when they do this. The engine temperature has been just fine. I always monitor the temperature when driving and it always stays in the same range.

 

[peterk9]

Perhaps water got into something it shouldn't have. If so, I wonder if time will dry it out? This particular issue hasn't been posted about before as fas I can remember. Hopefully, other members can add some input here. Please keep the thread updated if things change. Thank you.

Peter

 

[ProjectSHO89]

Most likely, the low speed fan's operational logic has been disabled allowing only high speed fan operation.

This is a PCM-controlled system, the PCM's logic dictates when the fans are supposed to operate and at what speed. Since A/C operation does require airflow through the condenser to facilitate heat rejection, the fans are supposed to operate on low speed initially with the PCM kicking them up to high speed should the high side pressure go too high, a sign of insufficient heat transfer out of the system.

In low speed operation, the fans are connected in series with each only getting half of the power as in high speed when they're connected in parallel with full battery power applied to each. So, the first question is to determine if BOTH fans are running in high speed or only one of them as a failure of the circuit for one of the fans (among other possible faults) will disable low speed operation.

Have you scanned for any DTCs that would be related to cooling fan operation (P048x)?

 

[peterk9]

Could the conditions described by the OP have caused this or would it likely be a coincidence?

Peter

 

[ProjectSHO89]

I'd suspect that water got where it wasn't supposed to given the timing of the onset of the malfunction.

If BOTH fans are indeed running only at high speed as reported, then the issue is likely in the BJB or otherwise in the control logic. Without access to the computer with a scan tool, all we can do is make guesses, hopefully educated ones.

 

[Nitroheli]

I'd suspect that water got where it wasn't supposed to given the timing of the onset of the malfunction.

If BOTH fans are indeed running only at high speed as reported, then the issue is likely in the BJB or otherwise in the control logic. Without access to the computer with a scan tool, all we can do is make guesses, hopefully educated ones.

Thanks for your valued input ProjectSHO89, I just returned from vacation so I wasn't able to reply sooner. Here's my update since I drove the Explorer on my vacation. I plugged in a basic code reader (OBD2 from BAFX Products) on my vacation trip. Unfortunately there are no reported codes that come up, and all the checks the code reader does are all good with the exception of an EVAC test for emissions which I will look into later. Both fans are still cycling on and off in high mode(about 15-20 seconds on, then off for 1 min. then repeat). This seems to only occur when the vehicle is going slow or stopped. This only occurs when the A/C is on. Once enough air flow is going through the condenser the fans don't appear to be cycling on and off. The vehicle has had plenty of time to dry out from any water that may have caused the issue but the problem still persist. Based on your comments I'll probably have to bring the car into a repair station or dealer to have them do a more in depth scan to check all the systems. I'm not familiar with the BJB you mentioned in your reply. I agree with your suspicions though about the control logic. I will try to do a little more searching on the internet to see if anyone has had this same issue. And I'll get a more in depth scan done on the car, maybe that'll tell us something.

I will update back here with my findings.

 

[peterk9]

I also have never seen the term "BJB" before and have no idea what it means.

Peter

 

[ProjectSHO89]

BJB = Battery Junction Box. That's the nomenclature that the service documentation uses to describe what the owners manual calls the Power Distribution Box aka "underhood fuse box".

I tend to identify things based on the service documentation.

 

[Nitroheli]

BJB = Battery Junction Box. That's the nomenclature that the service documentation uses to describe what the owners manual calls the Power Distribution Box aka "underhood fuse box".

I tend to identify things based on the service documentation.

Thank you for clarifying. Good to know.

 

[Nitroheli]

Thank you for clarifying. Good to know.

Thanks for your valued input ProjectSHO89, I just returned from vacation so I wasn't able to reply sooner. Here's my update since I drove the Explorer on my vacation. I plugged in a basic code reader (OBD2 from BAFX Products) on my vacation trip. Unfortunately there are no reported codes that come up, and all the checks the code reader does are all good with the exception of an EVAC test for emissions which I will look into later. Both fans are still cycling on and off in high mode(about 15-20 seconds on, then off for 1 min. then repeat). This seems to only occur when the vehicle is going slow or stopped. This only occurs when the A/C is on. Once enough air flow is going through the condenser the fans don't appear to be cycling on and off. The vehicle has had plenty of time to dry out from any water that may have caused the issue but the problem still persist. Based on your comments I'll probably have to bring the car into a repair station or dealer to have them do a more in depth scan to check all the systems. I'm not familiar with the BJB you mentioned in your reply. I agree with your suspicions though about the control logic. I will try to do a little more searching on the internet to see if anyone has had this same issue. And I'll get a more in depth scan done on the car, maybe that'll tell us something.

I will update back here with my findings.

Problem solved! ProjectSHO89, you were right in your suspicions about the BJB(Battery Junction Box) aka under hood fuse box. After another closer inspection of the square higher amp fuses in the BJB, I noticed all had shiny copper taps when looking under the plastic lenses with the naked eye except two of them. Using a magnifying glass, I now could see that the fuse wire's inside were blown. it's very hard to see these wires with the naked eye, and I didn't catch it the first time around. They looked fine when I first looked at them. Of the two fuses blown, one was for "Engine cooling fan #2 high speed), the other was for (Engine cooling fan #1 and #2 low speed secondary circuit. It cost me all of $10 dollars to get two new fuses at the Ford dealer. Now the cooling fans are operating normally once again.
My assumption is......when I drove through the flooded streets that one rainy day, I had the A/C on, the condenser fans must have been running at the time, and they got bogged down in the water, overloading the circuit and blowing the fuses. I'm just glad I didn't spend $130 bucks for a diagnostic check and who knows how much more from there had I listened to a dishonest mechanic LOL. I've learned to look at fuses much more closely next time. Thanks for you feedback, much appreciated.

 

[Nitroheli]

I also have never seen the term "BJB" before and have no idea what it means.

Peter

Peter, thanks for your input to my problem. Below is the fix and my reply to ProjectSHO89 for his help.

Problem solved! ProjectSHO89, you were right in your suspicions about the BJB(Battery Junction Box) aka under hood fuse box. After another closer inspection of the square higher amp fuses in the BJB, I noticed all had shiny copper taps when looking under the plastic lenses with the naked eye except two of them. Using a magnifying glass, I now could see that the fuse wire's inside were blown. it's very hard to see these wires with the naked eye, and I didn't catch it the first time around. They looked fine when I first looked at them. Of the two fuses blown, one was for "Engine cooling fan #2 high speed), the other was for (Engine cooling fan #1 and #2 low speed secondary circuit. It cost me all of $10 dollars to get two new fuses at the Ford dealer. Now the cooling fans are operating normally once again.
My assumption is......when I drove through the flooded streets that one rainy day, I had the A/C on, the condenser fans must have been running at the time, and they got bogged down in the water, overloading the circuit and blowing the fuses. I'm just glad I didn't spend $130 bucks for a diagnostic check and who knows how much more from there had I listened to a dishonest mechanic LOL. I've learned to look at fuses much more closely next time. Thanks for you feedback, much appreciated.