Kenmore model 116.59812991 about 20 years old. Three position switch: Off, Floor, Carpet. In Floor position, canister motor runs like it should. In Carpet position, canister motor runs as it should but agitator motor does not run. But if I substitute a different hose with switch from a similar newer model vacuum, the old vacuum canister motor and agitator motor both work perfectly in both Floor and Carpet switch positions. Therefore, I assume it's a bad switch, but is there anything else it might be, like a broken wire somewhere in the hose? No wiring diagram available from Sears, so I can't figure out how to troubleshoot the wiring. Thanks for any help. Jake