Customer Questions and Answers for Drive Motor by Bosch

Martin, Unfortunately the motor is a "sealed" unit and cannot be dismantled to test any of the internal components. You can test the motor winding's and the winding's for a short to ground, and or an "open" winding " Look on the motor connector after you pull it out. There are 5 terminals with blue wires. Numbered from 1-5 there is a locator's tab between # 1 and 2. Another tab between 3 & 4. The motor terminals are named from 1-8. # 1-3 are not used. # 4 & 5 are green ground or motor frame ground so you are left with # 6,7 and 8 motor terminals. Which correspond to the units wiring harness # 3-4 & 5 blue wires. Look at the unit supplied wiring diagram inside the cabinet and you will see exactly what is laid out. Measuring the motor terminals # 6 and 7 ohms value. Then measure # 7 and 8 value. Then measure terminal # 6 and 8 terminals. Then measure every terminal separate to the motor frame ground or to terminal 4-or 5 (ground). This checks that particular winding for a shorted winding. These winding's value should be all within 10% tolerance value's". You didn't mention a problem, so if the motor tests OK, you'll need to move to the next possible issue.