But only the Reverse Lights? That seems odd to me... Wouldn't it be a better approach to display a notification of Low Battery Level on the cluster? Maybe a bug that Lincoln overlooked by accident.
All vehicles these days have energy/management conservation programs. All vehicles have draws on the battery even when shut down & sitting. The longer a vehicle sits, the longer the drain. Manufacturers have built in safeguards to insure a battery has enough power to start a vehicle when battery reserve reaches a critical level. This is the level needed to have enough voltage/cranking amps to start a vehicle. The longer a battery sits, the more it loses efficiency. The longer a battery sits, the more it sulfates. This is why trickle chargers are so important in combating sulfation.
On many (I would say most)
vehicles started on a weak battery, have programming to devote more to initial battery charging by limiting certain functions until the battery reaches a healthy state of charge. This
might be the case on our Lincolns.
Regarding the backup lamp we are discussing, this setup (the output) has a long journey from BCM to tailgate LED. The BCM FET for the reverse light would require a low voltage signal (program input) to switch on a high voltage output to enable & deliver sufficient forward voltage needed to turn on the Rev. light LED)
In your case, you noticed the backup lamp flickering. It could be a few things, but what Kolectr (I believe) & I are alluding to is:
1). Possible battery program management to BCM FET controlling BCM output to Rev. light shutdown due to monitoring a low battery state of charge condition. This would be a built in safeguard.
2). The BCM might be delivering the (low voltage) input signal to the Rev. light FET, but the FET output (battery voltage) might be too weak to sustain the Rev. light LED from operating (low forward voltage to LED is to low).
3). Intermittent connection somewhere along the path from BCM output to LED.
Truth is, most all sitting vehicles upon start up are starting with some degree of battery inefficiency under 100%. The longer they sit, the more efficiency is lost, (state of charge).
If manufacturers enabled a low battery indication to let you know a low state of charge is present in a standing (sitting) battery, that would wreak havoc in the industry! Imagine everyone flooding dealer service depts. on a Monday morning stating battery light was on before they started their vehicle, but went away after starting!
Instead of alarming the user to a low state of charge before start up, programs manage battery condition before & after the vehicle is running, monitoring state of charge, and replenishing the battery after start up, ensuring all is well! The user is unaware of this seamless operation. Not an oversight at all.
In the old days, autos had battery voltage gauges or AMP gauges to let you know battery condition. Today, computers do all that for you!
