Can Trailer Brake Lights be Ran From Brake Controller Circuit  

I am restoring a 1946 Spartan Manor travel trailer. I replaced all the 110v and 12v lighting plus wires. All the exterior lights work, but there is a short delay between the time I depress the brake pedal and the “high beam filament” lights up. I tried LEDs, but they aren’t bright enough to illuminate the KD520 tail/brake lights very dark red, thick glass. The “low beam”, tail light filament in the incandescent 1157 bulbs connected to my brown wire are not bright, but the “high beam” filament is fine. I connect the trailer to a 2017 Ford F250 super duty with Ford’s brake controller. I know the brake controller is energizing the 1157’s high beam, because it lights up! But there is a nagging delay of about 3-5 seconds between pushing down on the pedal until the brake light function lights up. Not sure, but I don’t think there’s a delay if I squeeze the brake controller’s levers ?. Haven’t tried towing the trailer as yet, so don’t even have a way to determine if the brakes function. I replaced the wire from the blue terminal to the brakes it goes to the blue terminal in the junction box on the tongue where the Ford brake controller wire via the 7-pin plug joins the two wires. I don’t have that delay on my 1964 Fireball, nor our 2018 Montana: they both light up immediately when the pedal is depressed. Can there be an issue in the brake’s relay? Driving me nutsoid! The middle, higher light is the brake/tail light connected to the blue wire that also connects to thecbkue terminal on the tongue’s junction box its low beam filament connects to the brown wire for running/tail lights.

asked by: Jim