Section 28-921 - Applicability of equipment requirementsA. A person shall not:1. Drive or move and the owner shall not knowingly cause or permit to be driven or moved on a highway a vehicle or combination of vehicles that:(a) Is in an unsafe condition that endangers a person.(b) Does not contain those parts or is not at all times equipped with lamps and other equipment in proper condition and adjustment as required in this article.(c) Is equipped in any manner in violation of this article.2. Do an act forbidden or fail to perform an act required under this article.B. This article does not prohibit the use of additional parts and accessories on a vehicle if the use is not inconsistent with this article.C. The provisions of this article with respect to equipment on vehicles do not apply to:1. Trailers used solely in the operation of a farm for the transportation of the unprocessed fiber products on the farm or from the farm to a cotton gin, road machinery, road rollers, farm tractors or implements of husbandry when the implement is being incidentally operated or moved on a highway whether as a trailer or self-propelled unit. Notwithstanding this paragraph, a farm tractor equipped with an electric lighting system shall display at all times mentioned in section 28-922 a red tail lamp and either multiple beam or single beam head lamps meeting the requirements of sections 28-925, 28-941 and 28-943. For the purposes of this paragraph, "incidentally operated or moved on a highway" means travel between a farm and another part of the same farm, from one farm to another farm or between a farm and a place of repair, supply or storage.2. Vehicles driven by enforcement officers of the Arizona game and fish department in conducting night patrols and investigating night poaching activities.