Best way to make sure the ABS light is working correctly?

Pull on a slight angle to the left (drivers side), cycle your key off and on, light and trailer abs system should cycle

 

Piece of black tape always worked for me. They don't call it "A-BS" light for nothing.

 

Normal operation is as follows. Turn key on, light comes on for about 2-3 seconds, then goes off. That shows it’s working. If it stays on, or at any time comes on and stays on, there’s a problem. Blink diagnostic as follows. Turn key on for 1-2 seconds, off 1-2 seconds, on 1-2, and off 1-2, then on. Light will blink. Count blinks. Refer to Wabco or whatever brand system, (ecu) blink code chart. Fix problem, drive vehicle above 3-5 mph to turn light off. If light stays on, it’s either not fixed, or there’s another problem, repeat diagnostics and get new code. Repeat till light stays off.

 

And that is going into my tips and tricks manual lol. Ive been a driver for over a decade now and never knew that....would have made repairs SO much bloody easier on my last trailer.

 

That’s an awesome nugget of information right there. Thank you rideandrepair.

 

I unplug it to check, do it at night with all other lights off.

 

I checked it that way or like @skallagrime just turn the key off and back on.

 

Mine comes on for a second when I apply the brakes..is that normal? I’m wondering because I never noticed it on other trailers I’ve had.