Bryant.com, ManualsOnline.com and ManualsLib.com all have Bryant owner's and maintenance manuals that include service, parts, error codes and electrical diagrams and schematics for most models. Most units should have diagrams inside one or more of the access panels.
Models manufactured after 1990 have a tiny window that shows light, and when the power is turned off and then back on, it flashes a code. Owners can use the code to cross-reference with a chart and locate problems on the diagrams. Dirty or clogged filters are the primary maintenance and problem issue with forced air furnaces. The diagrams assist in locating the filters and providing specifications for replacements.