{"nhtsa_id":629001,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2002-03-26","date":"2002-01-18","document_id":"SB635005","mfr_campaign":null,"replaces":"SB635005","component":"VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM","mfr_system":null,"summary":"ON SOME MODELS, WHEN THE CAB CLIMATE CONTROL IS SET TO THE HEAT MODE, CAB TEMPERATURE MAY NOT REMAIN STABLE WITHOUT FREQUENT ADJUSTMENT OF THE TEMPERATURE CONTROL LEVER. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/629001","components":[{"id":"visibility","name":"Glass, wipers and mirrors","parent":null},{"id":"hvac","name":"Heating and air conditioning","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"MACK","model":"CH","year_from":null,"year_to":null,"match":"exact","vehicle_ids":[]},{"make":"MACK","model":"CL","year_from":null,"year_to":null,"match":"exact","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":[]}