What Causes Motor to Run Too Long on Lippert Electric Coach Steps  

Question:

Expert Reply:

If there is something causing a short it is possible that the motor could be running too long after extending or retracting and that could cause the problems. When replacing the parts make sure gears and other moving parts are properly lubricated as well. White lithium grease is good for this. Check the replacement and OEM parts for any signs of corrosion and any damaged wires that could be pulling current causing the motor to continuously run. It could also be an issue with the door switch.

The following are the troubleshooting steps that also might help:

1. Disconnect the plug between the chassis and the steps. Using a voltmeter, measure the voltage on the large red wire at the chassis connector with the step switch in the “ON” position. The meter should indicate more than 12VDC. Turn the step switch to the “OFF” position and the meter should not indicate voltage. If the meter indicated no voltage with the switch “ON”, check the circuit and the circuit protectors. If it indicates less than 12VDC with the switch “ON”, charge the battery. If 12VDC are indicated on the red wire with the switch “OFF”, replace the switch.
2. With the voltmeter, set to measure resistance, measure the resistance between the green wire in the plug and the frame of the vehicle. If there is more than one ohm of resistance, clean the ground eye (ground lug) or relocate the ground wire.
3. Using a voltmeter, set to resistance, test for ground on the brown wire going to the door switch. The meter should indicate an open circuit with the door closed and a path to the ground with the door open. Insure that the door is open at least 6 inches before it completes the circuit to ground.
4. With a voltmeter, check for 12VDC on the yellow wire with the ignition switch in the “ON” position and no voltage with the switch in the “OFF” position. If there is no voltage with the switch in the “ON” position, trace the circuit and repair.
5. Reconnect the steps to the chassis and proceed to test as follows. With step switch “ON” and the ignition key “OFF” open the entry door and the steps should extend and the light should come on.
6. If the light comes on, but the steps do not deploy, remove the step assembly from the motor home.
7. Remove the two bolts that hold the step arm collars to the drive shaft. This will allow you to operate the steps manually. If the steps do not operate freely, visually inspect for bent arms or tight joints. The shoulder bolts should rotate in the bushings with very little effort. Repair or replace as needed.
8. If the step moves freely, unplug the module from the motor assembly at the two pin connector. Connect 12VDC from the battery to the yellow wire going to the motor and ground the red wire. The gear should rotate in the deployment direction until it goes over center and comes to rest against the stop. (If the steps were deployed, reverse the wires to drive the gear in the opposite direction.) If the gear and motor assembly will not function normally replace them, otherwise replace the module assembly.

It goes on to say the following: It is not recommended that the tightness of the step be adjusted in the field. Some minor movement of the step is considered normal. Excessive movement could be an indication of a more serious problem and the bottom cover should be removed and a thorough visual inspection should be made before any attempt is made to repair the problem by adjusting the cams. The cams are located on the inside of each side plate. Should it be deemed desirable to adjust the cams, they can be adjusted by loosening the nut on the outside of the side plate, and rotating the cam and bolt so that they bear more heavily against the step arm. Care should be taken so that both cams are adjusted approximately the same amount. After adjustment, the steps should be operated several times to insure that they are still locking over center. This can be determined by watching the steps as they complete their deployment. If the steps are locking over center, they will deploy fully and then retract approximately 1/8” as they lock in place.

expert reply by: Michael H

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