high pitch sound after shut down

[praterben0517]

2012 Explorer battery draining

I have a 2012 explorer that has a humming sound under the hood when the engine is off and keys are out of ignition. Went to start it the next day and the battery had drained. Tried to jump it off and 2 relays started clicking. Fuel pump relay and run/stop relay. Took them out and replaced and still clicked. Unhooked battery and red connected and it jumped off. What could be the humming sound that is causing it to drain the battery. Is it a relay to something? Thanks.

 

[ObsceneJesster]

Maybe a fan?

 

[FordService]

I have a 2012 explorer that has a humming sound under the hood when the engine is off and keys are out of ignition. Went to start it the next day and the battery had drained. Tried to jump it off and 2 relays started clicking. Fuel pump relay and run/stop relay. Took them out and replaced and still clicked. Unhooked battery and red connected and it jumped off. What could be the humming sound that is causing it to drain the battery. Is it a relay to something? Thanks.

Welcome to the forum, praterben0517! Keep in mind that you can always bring this to the attention of your dealership; they're pros at diagnosing mystery noises. How many miles are on your Explorer?

Crystal

 

[praterben0517]

Thanks. There are 48000 miles on the explorer. Talked to the guy at dealership and sent a sound clip to them also to try to determine what it was. They said the next time it does it to try pulling fuses and relays to find the cause without bringing it in for a full diagnostic review. Only thing is that it's not giving any codes. Which fan should I check first? It's a high pitched hum.

 

[mprtech]

Not saying the noise is normal but my 2011 limited makes an extremely high pitch hum after I shut it off. Sounds like electrical noise, never caused me any issues and I've never tracked it down. The hum may not be your draw.

 

[praterben0517]

I tracked it down to a fuse and relay. It is the PCM fuse and the relay for the PCM keep-alive power,PCM relay, canister vent solenoid. Any one know about the PCM keep alive power. That sounds like what the problem is. It's keeping the explorer alive.

 

[peterk9]

I'm not that familiar with the electrical systems of the Explorer but I do know that there are circuits/systems that must be kept 'alive' to retain certain memory functions.

Peter

 

[fx8racer]

High Frequency sound after shutdown drains battery

Hi everyone, I have always owned ford trucks but I am new to the 5th generation Explorer.Let first say owning a 2011 xlt has been pretty painful, one thing after another! My issue this past week is everytime I turn off the truck a high frequency sound stays on under the hood and drains the battery. I saw this issue posted but had trouble finding the post. I have it scheduled for service this Friday but the dealer seemed like Hmmm never heard of this issue. I am affraid I will be taking it in multiple times for this unless I can gain some insight from anyone who might have had this issue. BTW the battery is a brand new motorcraft maxx.

Thanks,

 

[peterk9]

Welcome to the Forum fx8racer.:wavey:
Does this noise stay on until the battery is dead or does it stop after a period of time? Usually if a noise persists for a while it should make it easier to try and isolate where it is coming from.
I have merged your thread with this existing that may have been the one you referred to.

Peter

 

[FordService]

Hi everyone, I have always owned ford trucks but I am new to the 5th generation Explorer.Let first say owning a 2011 xlt has been pretty painful, one thing after another! My issue this past week is everytime I turn off the truck a high frequency sound stays on under the hood and drains the battery. I saw this issue posted but had trouble finding the post. I have it scheduled for service this Friday but the dealer seemed like Hmmm never heard of this issue. I am affraid I will be taking it in multiple times for this unless I can gain some insight from anyone who might have had this issue. BTW the battery is a brand new motorcraft maxx.

Thanks,

Welcome to the forum, fx8racer. How many miles are on your Explorer? I'll investigate options to help.

Crystal

 

[fx8racer]

Thanks Crystal, There is roughly 48k on the Explorer.

 

[fx8racer]

Peterk9 thanks, the noise in the past has shut down after a few minutes like other people have mentioned, but most recently as of this past weekend the noise stays constant overnight and ultimately drains the battery. I spoke to the dealer again this morning after my first call and they are leaning towards the cooling fan. The fan isn't moving during the high pitched sound but could be bad electric motor. I hope they can solve this.

Thanks again

 

[FordService]

Thanks Crystal, There is roughly 48k on the Explorer.

Let me know how things go on Friday, fx8racer. If you need help after your appointment, I'll be here.

Crystal

 

[peterk9]

Thanks Crystal, There is roughly 48k on the Explorer.

I just merged another thread with this one. Check out post 66.

Peter

 

[Rodomontade]

Noise is the VFD Variable Frequency Drive for the cooling fan.

My Audi has it and also makes this noise.

NORMAL

 

[peterk9]

Not sure how it can be considered normal if the sound persists to the point that it drains the battery.:scratch:

Peter

 

[fx8racer]

There is nothing "Normal" about it, if you shut off the key and hear the high frequency sound and it doesn't stop in a minute or so, go back and check a few hours later and if you still hear the noise I can guarantee your battery will be near dead by morning.

 

[fx8racer]

Finally, getting the Explorer back today from the Dealer. The high frequency noise was coming from the cooling fan motors or motor when the key was turned to on, but engine not running. They couldn't duplicate the problem when I took it in Friday, they could hear the noise, but it turned off with the key out, so they kept it a few days. The service manager finally approved replacing the part, he said there was a recall and overheating issues with the 2011 model. I will give everyone an update as to if the new motor makes noise in the on position, and if the noise shuts off with the key out of ignition. I will be so happy if this solves the battery draining issue.

 

[peterk9]

There were a lot of issues with the cooling fans, especially with the 2011 models. You should also check with the dealer to see if the Customer Satisfaction Program 12B36 was ever done on your vehicle. This reprogram caused the fans to intermittently run at a high speed to avoid possible contamination of the fan motor contacts.

http://www.explorerforum.com/forums/showthread.php?t=387260&highlight=customer+satisfaction

Peter

 

[FordService]

Finally, getting the Explorer back today from the Dealer. The high frequency noise was coming from the cooling fan motors or motor when the key was turned to on, but engine not running. They couldn't duplicate the problem when I took it in Friday, they could hear the noise, but it turned off with the key out, so they kept it a few days. The service manager finally approved replacing the part, he said there was a recall and overheating issues with the 2011 model. I will give everyone an update as to if the new motor makes noise in the on position, and if the noise shuts off with the key out of ignition. I will be so happy if this solves the battery draining issue.

Thanks for the update, fx8racer. Definitely keep us posted about the repair; if I can do anything to help, you know where to find me.

Crystal