Home › CDL Practice Tests › Air Brakes Questions › Question 246
If the service and emergency lines were cross-connected, what problem could result?
- A.Cross-connection doubles trailer braking power safely
- B.The trailer might not charge or brake as designed, and its brakes could behave abnormally or fail to apply correctly with the pedal
- C.Nothing changes because both lines do the same job
- D.Only the trailer lights are affected
Correct answer
B. The trailer might not charge or brake as designed, and its brakes could behave abnormally or fail to apply correctly with the pedal
Why
Supply and signal functions are different, so swapping the lines corrupts both charging and brake command. Coupling checks and a trailer brake test are how a crossed connection is caught before the road.
Manual topic: Air Brakes - Trailer Air Brakes · From the Air Brakes practice bank (AB-246).