Rhythmic / pulsating static on AM radio only when moving

[Exit32]

I realize that I'm probably the only one here who listens to AM radio, but there's a local oldies station I tune into once in a while. Problem is, my Explorer's AM radio generates loud, pulsating static noise to the point where all I can hear is the pulsating static.

The weird thing is this only happens when my Explorer is moving. If I'm stopped at a traffic light or stop sign, the AM radio signal is crystal clear -- until I start moving again.

I've paid attention to nearby power lines and utility cables, and the pulsating static does not seem to come from those. Rather, it appears that something within the Explorer generates this AM interference, but only when the vehicle is moving.

Before I take my Explorer back to the dealership, I'd like to know if other 2020 Explorer owners have experienced this AM radio issue and determined the cause of the annoying pulsating static. Thanks!

 

[dstewart51]

Your not the only one who listens to AM Talk. I have seen the exact same issue since day one on mine. You will also find the noise only appears once the truck is warmed up. Yes, the Explorer is generating the interference and I believe its inherent with the vehicles electronic design. Its unlikely there will be a fix, the dealer wont have a clue unless Ford releases some kind of service bulletin, of which I'm not very hopeful.

I've gone over in my mind what on the vehicle could cause the noise, its a perfectly rhythmic pattern, only happens when its warmed up, only happens when moving and the intensity ramps up with speed up to a limit. I cant think of anything that would cause this. Need to use a RF Spectrum Analyzer with an EMI wand with the truck running in gear on a rack.

I keep thinking it has to do with the ultra sonic sensors. These emit audio in the 40-70 KHz range but the electronics that generate the audio could be at fault. If the signal is not a clean sine wave this could easily generate harmonics in the AM frequency range up to 1+ MHz.

Radar and Ultrasonic Sensors Strengthen ADAS Object Detection

The ultra sonic sensors would make make sense with the noise pattern and intensity increasing to a limit with speed.

 

[Exit32]

Good to know I'm not alone with this issue. Could be the vehicle's ultrasonic sensors, but this my third Platinum (2016, 2018, and now 2020) and all three are equipped with ultrasonic sensors. I didn't experience this pulsating AM radio static on my 2016 or 2018 Platinum, but it's possible the 2020 uses different sensors.

I was thinking it's the onboard wifi or cellular systems transmitting location info to FordPass when the vehicle is in motion, but I still get rhythmic AM static with those settings turned off.

Interesting that you mention it's only when the vehicle is warmed up. I'll have to check to see if my AM static is missing on my Explorer before the engine warms up.

 

[N3DD]

Curious.... Does the pulsing go away on AM HD signals or just AM analog reception?

 

[Exit32]

Curious.... Does the pulsing go away on AM HD signals or just AM analog reception?

Had a chance to experiment with HD Radio signals. We've got lots of HD Radio programming broadcast by FM stations in the Boston area, and HD Radio reception is great on the radio in my 2020 Explorer when in FM-reception mode.

When I switch to AM, I do not see any option to listen to HD Radio broadcasts. I'd guess it's because the AM stations are not broadcasting an HD Radio signal. So, to answer your question, I don't know if the rhythmic pulsing static I experience with analog AM signals goes away on AM HD Radio signals because, apparently, I don't have any AM HD Radio broadcasting in my area.

 

[dstewart51]

I've never see mine detect the AM HD signal even at work (well within range of many AM HD signals).

 

[blwnsmoke]

What's AM?

 

[Exit32]

AM stands for Amplitude Modulation. It is one of the most popular radio broadcast standards in the world.

 

[peterk9]

What's AM?

That's when I get up.

Peter

 

[dstewart51]

Once I got in to Los Angeles this morning I found the setting to enable AM HD radio (under settings then radio). Turns out it was set to off by default.

At least the AM HD function works. I don’t think you will ever hear the pulse static interference when decoding the HD subcarrier. Two reasons, the very nature of the digital decoding and two, the pulse interference is somewhat weak, it only covers up marginal and weak AM signals at which point your out of range of the HD subcarrier signal anyway.

 

[dstewart51]

On the way home;

 

[Exit32]

That's exactly the same pulsing, rhythmic static I hear on my Explorer's AM radio. Thanks for posting that video, dstewart51.

 

[ElectronFlow]

Made me think of the metal shielding that was put on early Corvette ignition
distributor caps and spark plug wires before the invention of FM (frequency modulation)
because of their fiberglass bodies.

I'm pretty sure aluminum body panels aren't being used in the new generation Explorer,
is the hood and/or firewall/subframe aluminum?

Shame one would have to place a Faraday Shield between the engine/ultrasonic sensors
and AM receiver. Not around the AM receiver.

 

[dstewart51]

Not sure what the hood is made of, but it’s not steel (not magnetic). I don’t think the EMI is ignition related due to the rhythmic consistency.

I remember the Corvette ignition shielding well, my first car had it;

 

[ElectronFlow]

The "Blind Spot" BLIS Cross Traffic-Alert
FORD CO-PILOT360™
system could be the culprit then.

 

[dstewart51]

The "Blind Spot" BLIS Cross Traffic-Alert
FORD CO-PILOT360™
system could be the culprit then.

Very well could be. I dont think Ford will have a fix for this any time soon.

 

[peterk9]

Not sure what the hood is made of, but it’s not steel (not magnetic)...........

It is likely still an aluminum hood as in the 5th generation. That hood was prone to "bubbling" issue along the front end. Hood Paint bubble issue only

Peter

 

[scoutexplorer]

I have an XLT and experience the same pulsating noise on AM.

 

[Forddealz]

The only time this pulsating sound was happening when I was using a fake I phone charger ( it was cheaper and i bought it at a gas station). I have not heard pulsating sound again for 4 weeks. Fake cord also disconnected my carplay and waze navigation map was off.

Make sure you guys have legit I phone chargers / cords.

 

[Exit32]

The only time this pulsating sound was happening when I was using a fake I phone charger ( it was cheaper and i bought it at a gas station). I have not heard pulsating sound again for 4 weeks. Fake cord also disconnected my carplay and waze navigation map was off.

Make sure you guys have legit I phone chargers / cords.

I don't have any chargers or cords in my Explorer, and I still experience the annoying, rhythmic, pulsating static that overwhelms AM radio broadcasts to the point of making them unlistenable.