Rev: 12.15.21 Page 8 CCD-0005300
2. If battery drain is suspected, observe the under-step light while the step is extending.
To determine if a control unit is not shutting off, which would also cause a drain on the battery, do
asfollows:
1. Remove the four-way connector to the chassis and the two-way connector between the step motor
and the control unit. See Wiring Diagram.
2. Place a voltmeter between the red and yellow motor wires at the two-way connector from the control
unit. Reconnect the four-way connector.
3. Turn the step override switch on. If any voltage registers on the voltmeter for more than five seconds,
the control unit is not shutting off and may be defective.
NOTE: When doing this test, switch the voltmeter leads back and forth between the red and yellow motor
wires to make sure no voltage registers.
4. If any voltage does register, disconnect the four-way connector to keep the step motor from
overheating.
5. If no voltage is present, the control unit has shut off and is normal.
If the step assembly does not work or operates erratically, such as extending only part way and then
shutting off, the first item that should be checked is the vehicle's battery.
1. Low supply voltage may cause erratic operation of the step.
2. Poor ground connections may also cause erratic operation of the step assembly.
3. Check battery voltage and condition.
A. A battery in good condition that is properly charged will have a voltage reading of approximately
12.6 volts with no load.
B. Check the voltage at the battery and also at the four-way connector located on the control unit.
C. Make sure that all battery and step control unit connections are clean and secured.
D. Recharge or replace the battery as necessary, then retest the step for proper operation.
The step assembly may operate erratically if the step is being operated directly from a converter, where the
output from the converter is not adequate or properly filtered for a clean DC voltage.
NOTE: The converter MUST be capable of producing a minimum of 30 amps for proper step
assemblyoperation.
If the ground to the control unit is lost, either between the step control unit and the vehicle chassis (the long
green ground wire) or between the vehicle battery and the ground (negative battery cable), the step will not
function.
1. Make sure the battery terminals and all wire connections are clean and tight.
2. Verify that all wires meet the minimum requirements. See Wiring Diagram.