My trailer has a screw loose...

The truck I drive has a neat feature that test all the electrical systems including the ones on the trailer. Well the anti-lock brake light didn't come on so some trouble shooting was needed. There are three common causes for this. A dirty connection, a broken connection or a burned out light bulb. Before you check those though you need to do a standard truck start as that will test the ABS system too. The system said it was fine. Well...   Going under the trailer and physically checking the connections I found the top half of the "system" loose. Actually missing several nuts and a bolt to secure it. Not a good way to start the day but...

Ended up getting home really late which means I will have to look at blips hopefully tomorrow.