{"nhtsa_id":10076464,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2016-07-14","date":"2015-10-01","document_id":"83-25","mfr_campaign":null,"replaces":null,"component":"VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM","mfr_system":null,"summary":"Side Window Defroster and Cooling Improvement Retrofit This procedure improves the side window defrost function and overall A/C performance on Western Star 4700, 4800, 4900, 6900 models. In extreme cold conditions, the side windows may ice up and limit visibility. A retrofit kit (WWS RD-3-19025-0) is available to remedy the side window issue. See Fig. 1 for installation parts. Installation of the new louvers directs air flow to the side windows. Installing the fresh-air door-stop bracket, and sealing leaks in the A/C ducting, significantly improves air flow in heater/defrost and cooling modes, providing noticeable improvement in overall system performance.","document":null,"url":"https://open.wenmarpro.com/bulletins/10076464","components":[{"id":"visibility","name":"Glass, wipers and mirrors","parent":null},{"id":"hvac","name":"Heating and air conditioning","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"WESTERN STAR","model":"5900","year_from":null,"year_to":null,"match":"exact","vehicle_ids":[]},{"make":"WESTERN STAR","model":"CONSTELLATION","year_from":null,"year_to":null,"match":null,"vehicle_ids":[]},{"make":"WESTERN STAR","model":"HERITAGE","year_from":null,"year_to":null,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}