Entry Step ProblemsPopular
Common Problems / Posted 2 years ago / 1135 views
Entry Step Problems
This write-up covers SCS/Frigette and Kwikee/Coach brand steps.
(Data sources: Owner’s Manual, & BCS Forum)
(Author thanks Fred Brooks for his review and comments)
(SCS Frigette was acquired by Lippert so this may be applicable to many Kwikee & Coach steps)
The logic controller provides signals to open and close the step based on the status of the Ignition Switch, Step Switch and the Entry Door (by a magnetic door switch).
|Ignition||Step Switch||Entry Door||Step||Step Light|
|On to Off||Open or Closed||Remains in position||Off|
Many steps have self-lubricating bushings so added lube should not be needed. If lubrication is required, use silicon based grease or spray. The step mechanism is exposed to road dirt due to its location so a periodic cleaning with compressed air or brush may be appropriate. Use of water is discouraged as water ingress to the controller can cause controller problems/failure.
Use Loctite when replacing bolts or nuts. If replacing a rivet with a bolt, be sure to use nylon locking nuts.
4 wires feed the logic controller via a 4 pin connector (C1).
- Red; Battery voltage (fused).
- White: Step switch (will have battery voltage when switch is On).
- Yellow: Ignition over-ride (retracts step when ignition is On).
- Brown: Signal from door magnet switch.
Wiring Diagram at end of article.
The controller output is via a 2nd connector with red and yellow wires (C2). There is also a wire to the step light coming directly from the controller and a Green ground wire.
Proper Voltage and Ground:
Disconnect C2 and measure the voltage on the Red wire with the Step Switch ON. You should measure 12+ volts (battery voltage). If no voltage is present, check for blown fuses or a faulty Step Switch.
With the Step Switch OFF there should be no voltage present on the White wire. If voltage is present, the Step Switch is probably faulty.
If voltage is low, check the battery voltage and recharge if needed. If battery voltage is 12v+, check the resistance between the Green wire (not in the connector) and the frame. If more than 1 ohm, clean the ground lug and frame attach point.
Door Magnet Switch:
With a VOM set for resistance, check for ground on the Brown wire coming into C1 (check on input to connector, not on controller side). You should read open on the VOM when the door is either open or closed and ground when the door is the other position (open or closed). If these readings are not present a bad magnetic switch is probably the culprit. You can use an external magnet to verify if the magnet in the door or the door-jam switch is faulty. You may need to rotate the external magnet to align the polarity field.
Verify there is 12v+ on the Yellow wire coming into C1 when the ignition switch is ON and 0V when the ignition switch is OFF. If no voltage is present, check for a blown fuse. This wire is connected to ignition activated power.
Reconnect C2. With the Step Switch ON and the Ignition OFF, open the Entry door. The steps should extend and the step light should come on. Less than 3 seconds (normally about 1 second) after the steps reach full extension, the step light should get brighter, indicating that current to the step motor has been shut off. If the light does not dim, the controller is probably bad and requires replacement.
If step does not extend but light comes on, the mechanical step mechanism may be binding. Remove the step assembly from the coach. Then remove the 2 bolts holding the step arm collars to the drive shaft, enabling you to operate the steps manually. The step mechanism should operate freely. Check for binding and repair as needed.
If the step moved freely, remove the splash guard and unplug the motor assembly at C2. Connect 12v to the Yellow wire going to the motor and ground to the Red wire going to the motor. This should activate the motor and the gear. If the gear doesn’t move, it may be against the stop. Reverse the 12V and Ground and the gear should rotate. Reversing 12V and ground again should cause the gear to rotate back to its initial position. If the gear or motor do not function correctly, replacement is indicated. If they do function as expected, the controller is probably bad.
Kwikee Steps Service Manual: http://www.rvtechlibrary.com/exterior/kwikee_svc_manual.pdf
Temporary Field Repair: Steps won’t retract. Remove cotter key and pin. Retract steps manually and secure with wire, bungie cord, etc. https://www.youtube.com/watch?v=4G9MJ6Akw0k
Magnetic Reed Switch: If you change out the step assembly, be sure to also change the magnetic reed switch in the door jam. The original White switches were “normally open”. The current Black switch is “normally closed”. If you don’t change it out, the step will work opposite of normal when the door is opened or closed.
Kwikee Step Won’t Extend After Storage: Kwikee replacement steps have a “last man out” feature. If the step is in the stow position and the entry switch is OFF, the controller capacitor stores enough energy to extend the step one time. With long storage times, the capacitor can lose enough energy to prevent step extension. Sometimes this capacitor loses its charge and the step won’t extend after stowage. Starting the coach should cause the steps to work normally.
Step Light doesn’t work:
- Bad bulb: Lens can be removed with knife blade.
- No Power: Check wiring. Broken wires are not uncommon. Also verify there is a good ground connection.
- Bulb & Wiring and Ground OK: Possible bad controller.
Dash Step Out Light Stays On: Check the magnet on the steps.
A brief discussion of controller operation and the effects it has on the motor and step chassis. When the step cannot physically extend any further, the motor starts to draw more amperage trying to continue to extend it. The controller senses the increase in amperage and shuts the motor off and resets itself to operate in the opposite direction the next time it is asked to operate. This allows the step to run into obstacles like curbs without damage. The same logic occurs when it retracts. The motor/controller “remembers this and usually always stops in the same position when extended or retracted. Over time this stresses the motors commutator and armature. Removing the motor and temporarily cycling it will reorient the armature to a new location inside the motor. When reinstalled, the motor now starts in a new location internally. Note that some shops will want to replace the motor if the steps don’t fully extend, even though the above procedure will fix the issue.
When preparing to reinstall the motor, first pull the cotter pin and then the ¼” pin out of the transmission arm and step bracket. Unplug the 4pin plug that powers the step. With the arm disconnected, temporarily plug the 4pin plug in just for a second. This leaves the arm somewhere in between extend and retract. Now you can shift the steps in and out to align and install the ¼” pin and cotter pin.
Caution! Please be careful. You are dealing with scissor assemblies that can hurt you. Please be mindful of where your hands and fingers are when you activate the step when working on it!
Most use an automotive window lift motor;
- (Siemens “Window Lift Motor”, part number WL43003 used on a variety of Fords). http://www.ebay.com/itm/Siemens-VDO-WL43003-New-Window-Motor-/171206078221
- Remove motor and take to auto supply store, e.g. NAPA