Trailer Brake Chime
 

I just bought a new 2020 F150 to replace my 2012. I was pulling a trailer and, as I have done on the past used the trailer brake controller to help slow down the load. As before, the trailer brake window pops up on the productivity display showing me how much brake I am giving it. However, now I get a really annoying warning chime (as if it wanted to warn me of something I already knew: that I was applying the brakes). If anyone has any info on why it chimes (dings, alarm, etc) and/or if there is a setting to shut it off, I would appreciate it. Thanks!

What message pops up when the chime goes off? I only get the chime when something is wrong, like it can't see the trailer brakes, and a message accompanies the chime.

The only thing that pops up is a box that says (I think) "Trailer Brake" with a blue bar under it that fills from left to right depending on how much brake I am applying with my fingers on the controller and the number cooresponding to the output amount.

This occurs while depressing the brake pedal, or the brake slide switch?

it occurs when using the brake slide switch. I believe it happens regardless of whether or not my foot is braking. Somehow, I wound up on another, similar thread which I did not find earlier when searching. Someone mentioned deleting the saved trailer and adding again which I will try. I know the brakes are activating because I can feel it when they do (this means at least ONE side is activating anyway).

Deleted trailer and reinstalled it with no change. Sanded inside of 7 way plug and added dielectric greade. No change. brakes are electric over hydraulic and i hear the pump going and i know the brakes are working when I drive it. Still chimes as if no trailer is connected when I operate the trailer brake with my hand.

The Ford brake controller is sensitive to the trailer brake system circuit resistance and the message can be displayed if the trailer brake system circuit is outside that spec. Have you verified that all connections in the trailer brake system are in good shape (besides the 7-way plug)? Most trailers have cheap crimp caps connecting the individual brake magnets to the main trailer brake wiring which can cause poor connections, I have found this to be the issue on our old travel trailer. The solution was to solding the connections and use water proof shrink tubing (has a adhesive infused in the shrink tubing) from homedepot to resolve the issue -> https://www.homedepot.com/p/14-8-AWG...2710,2789,2709. While correcting the connection issue's this is a good time to test the magnets individually for proper resistance and that none of them are shorted. Resistance should be between 3 and 4 Ohms per magnet (depending on brake diameter).

Total system resistance (measured between the 7-way plug and the trailer ground) = 1/R1 + 1/R2 + 1/R3 + 1/R4

Example (trailer magnets are rated at 3 - 4 Ohms -> using a nominal 3.5 Ohms for this example):
Resistance Total = 1/3.5 +1/3.5 + 1/3.5 + 1/3.5
= 0.2857 +0.2857 +0.2857 + 0.2857
= 1.1429 Ohms

Here are a couple of resources for information on troubleshooting electric trailer brakes:
https://www.etrailer.com/faq-testing...-function.aspx
https://www.dexteraxle.com/docs/defa...s.pdf?sfvrsn=2
https://forums.24hoursoflemons.com/v...c.php?id=19901

I can dig deeper for sure. Two big picture questions:

1. If there was an issue with wiring,, wouldnt I receive an error from the truck? Everything I SEE indicates normal operation, but I HEAR the chime.

2. If it was a trailer issue wouldn't I get the chime when I applied the truck breaks as well as the slider bar on the controller?

Before I start digging into the wiring I think I might bring it to a trailer store and plug in 1 or 2 new trailers to see if I get the same result. If I do then in all likelihood something in the truck not the trailer.

It wouldn't take but a second to measure the trailer brake system total resistance -> measure between the seven way plug and the trailer ground. At least at that point you would know whether or not the trailer brake system is in the pull park.

4 brake system - Total resistance (3 Ohms) = 1.3333 Ohms
Total resistance (4 Ohms) = 1 Ohm

2 brake system - Total resistance (3 Ohms) = 0.6667 Ohms
Total resistance (4 Ohms) = 0.5 Ohms

OP has electric over hydraulic, there is a single actuator.