# trailer or dolly does not cycle when electrical power is applied (a) only to the vehicle's constant ABS power circuit, or (b) only to the vehicle's stop lamp circuit — Vehicle inspection defect categories: MOT major, minor and dangerous verdicts

For trailer or dolly does not cycle when electrical power is applied (a) only to the vehicle's constant ABS power circuit, or (b) only to the vehicle's stop lamp circuit, category is Reject; inspection item number is 1; defect reference is l.(4); inspection item is Brake System; authority is US 49 CFR Appendix A to Part 396, recorded from its source on 2026-08-06.

- **Defect:** trailer or dolly does not cycle when electrical power is applied (a) only to the vehicle's constant ABS power circuit, or (b) only to the vehicle's stop lamp circuit _(verified: appears in the quote below)_
- **Category:** Reject
- **Inspection item number:** 1
- **Defect reference:** l.(4)
- **Inspection item:** Brake System
- **Authority:** US 49 CFR Appendix A to Part 396 _(our reading, not quoted from the source)_

## What the source says

> trailer or dolly does not cycle when electrical power is applied (a) only to the vehicle's constant ABS power circuit, or (b) only to the vehicle's stop lamp circuit.

## Source

- https://www.law.cornell.edu/cfr/text/49/appendix-A_to_part_396

Last verified: 2026-08-06. Review by: 2027-02-02.
Part of [Vehicle inspection defect categories: MOT major, minor and dangerous verdicts](https://referencesource.org/vehicle-inspection-defect-categories/).