QM-7 SERIES SERVICE MANUAL
PAGE 3.5
JANUARY 2012
SUNRISE MEDICAL
1. Check that the batteries are fully charged
and in good condition; and check all cables and
connections. Check the connections to the left
motor, look for a loose or damaged connector.
2. Measure the resistance from the bottom
contact of the red thick wire on the 4-pin left
motor connector to each of the top contacts of the
connector (figure 3.5.1). Measure the resistance
from the bottom contact of the black thick wire on
the 4-pin left motor connector to each of the top
contacts of the connector (figure 3.5.2). If all of
the readings are open, then replace the controller.
If any of the readings are short, then replace the
left motor.
Three Bars - Left Motor Wiring Trip
Fig 3.5.1
Test 1
Test 2
Test 3
Test 4
1. Check that the batteries are fully charged
and in good condition; and check all cables and
connections. Check the connections to the right
motor, look for a loose or damaged connector.
Four Bars- Right Motor Disconnected
2. Use the meter to check the resistance across
the two bottom contacts of the thicker wires on
the 4-pin motor connector as shown in (figure
3.5.3). If the meter reads between 0 to 1.5 ohms,
then replace the controller. If none of the above
corrects the problem, replace the right motor.
Section 3
Fig 3.5.2
Fig 3.5.3
3. Use the meter to check the resistance across
the two bottom contacts (thicker wires) on the
4-pin motor connector as shown in (figure 3.4.5).
If the meter reads between 0 to 1.5 ohms, then
replace the controller. If none of the above
corrects the problem, replace the left motor.
Fig 3.4.5
