Cacophonous relay clatter

[inmanlanier]

This is mostly a rhetorical post - but if any of you have sat in your car, engine off for any period of time I'm assuming you've heard what I have, yes? This doesn't seem to matter how you got there... the conditions are: engine off, you are in the car, your key fob is also in the car (maybe not as well), and you may or may not be listening to Lincoln's fine audio system.

What I've noted is that there are multiple times where you hear all around you various relays energizing and/or de-energizing. It's kind-of funny, but as an engineer I'm really curious what modes of operation the Lincoln engineers programmed. I see no action as a result of the noise (light coming on/going off, doors opening/closing, audio starting/stopping). You just hear this not very subtle litany of clicks and clacks.

Anyone else had this pique your curiosity or simply make you wonder?

 

[rjabend]

This is mostly a rhetorical post - but if any of you have sat in your car, engine off for any period of time I'm assuming you've heard what I have, yes? This doesn't seem to matter how you got there... the conditions are: engine off, you are in the car, your key fob is also in the car (maybe not as well), and you may or may not be listening to Lincoln's fine audio system.

What I've noted is that there are multiple times where you hear all around you various relays energizing and/or de-energizing. It's kind-of funny, but as an engineer I'm really curious what modes of operation the Lincoln engineers programmed. I see no action as a result of the noise (light coming on/going off, doors opening/closing, audio starting/stopping). You just hear this not very subtle litany of clicks and clacks.

Anyone else had this pique your curiosity or simply make you wonder?

I have not heard what you are describing and frequently sit in the car waiting for my wife with both a running motor and with the motor off and, of course, the vehicle is on or off when the engine is not running. I have the air suspension which makes clicking noises, as it should while making adjustments in the vehicle height. If it is actually relay clatter it could be caused by a marginal relay input voltage, a defective relay, a continuously varying input to the relay . . . . . I always have my key FOB with me.

PS - Just thought I would add: In my world, "relay chatter" is a relay rapidly contacting then disconnecting continuously making a chattering noise.

 

[Action]

The sound is multiple electronic circuits powering down after the ignition key is turned off.
The clicking sound are relays that were engaged and are clicking open.
If you were to measure current draw during the first 10 to 30 minutes after key off, you would see an electrical draw that decreases a number of times. Even after that there is still a very small amount of parasitic electrical draw. (in milliamps) That draw will drain a battery, however it takes weeks to do so.

Circuits like interior lights or head lamps that are auto on/off. Or PATs system that does not engage until key off and doors locked and closed. All electronics will continue to draw some power, many of those are on a relay that opens at some point shortly after shut down to eliminate that draw.

If I wanted to research it, I am sure I could find at least a half a dozen circuits (depending on optional equipment) that are still engaged with key off. Eventually they power down. The key off just shuts down the engine run circuits. And initiates relay shut down for a number of other circuits. Just like the entertainment system is not off when the on/off button is selected. You can not play tunes on the FM and the system is still drawing power.

System power up is similar. There is a delay on startup to reduce the load on the charging system. That delay is usually only seconds in duration. And you do not hear it because of starter engagement and engine run cycle. In addition, on cold start (no matter ambient temp) the idle speed is elevated to burn off an enriched engine start fuel charge.

Action

 

[peterk9]

This is mostly a rhetorical post - but if any of you have sat in your car, engine off for any period of time I'm assuming you've heard what I have, yes? This doesn't seem to matter how you got there... the conditions are: engine off, you are in the car, your key fob is also in the car (maybe not as well), and you may or may not be listening to Lincoln's fine audio system.

What I've noted is that there are multiple times where you hear all around you various relays energizing and/or de-energizing. It's kind-of funny, but as an engineer I'm really curious what modes of operation the Lincoln engineers programmed. I see no action as a result of the noise (light coming on/going off, doors opening/closing, audio starting/stopping). You just hear this not very subtle litany of clicks and clacks.

Anyone else had this pique your curiosity or simply make you wonder?

Yes, this is very common and also applies to the 6th gen Explorer. I have also heard them at times when I'm in the garage and the vehicle has been sitting a while.

Peter

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[inmanlanier]

Yes, this is very common and also applies to the 6th gen Explorer. I have also heard them at times when I'm in the garage and the vehicle has been sitting a while.

Peter

Exactly my observations. Odd, but that's apparently how they have programmed it.

The sound is multiple electronic circuits powering down after the ignition key is turned off.
The clicking sound are relays that were engaged and are clicking open.
If you were to measure current draw during the first 10 to 30 minutes after key off, you would see an electrical draw that decreases a number of times. Even after that there is still a very small amount of parasitic electrical draw. (in milliamps) That draw will drain a battery, however it takes weeks to do so...

Action

It's the multiple different times at quite delayed periods after shutting down that I found to be curious.

 

[rjabend]

My lights and other turn offs seem to occur within several minutes of turning the engine off . . . . .then nothing apparent.

 

[Action]

It's the multiple different times at quite delayed periods after shutting down that I found to be curious.

Items that could still be on after key is off
Radiator fan circuit
Dynamic suspension system
PATS
Auto headlamp
Interior lamps
Memory seats & mirrors
Folding mirror circuit
Ignition key warning circuit
KAM - keep alive memory
Battery junction box
Systems that allow you touchless lock and unlock and/or push button start. Or using phone as a key.
WIFI enabled

Some of these are always on, some are shut down after a wait period. Most of these are beyond my skill level which is why I still have a 2006 model Lincoln.

Action

 

[BadgerChad]

Maybe I got a special model, my relays shut down to the tune of In-a-gadda-da-vida and take 17 minutes to fully turn off.

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[rjabend]

Maybe I got a special model, my relays shut down to the tune of In-a-gadda-da-vida and take 17 minutes to fully turn off.

Mine are approximately the same as yours.

 

[inmanlanier]

Mine are approximately the same as yours.

I hadn't put a timer on it - but that description sounds about right. Interesting to say the least.