Here is a lot of info that may help diagnose electric step problems.
I just completed repair on my electric steps and it was much easier than I originally thought. My symptom was the steps would not extend no matter what I did. This happened once before but cleared up when I started the engine which raised the voltage a tad which resulted in the steps extending and working fine for awhile.
This time the voltage increase had no effect.
So I armed myself with all the electrical info I needed to troubleshoot the problem. Being an electronic tech, this troubleshooting should be a snap. Simple circuit as long as the problem would stay put while I took measurements.
I crawled underneath to see what I could access and it appeared to be hard to access everything while laying on my back and reaching around the hardware. I decided that working on it this way was a job for my son who is much thinner, younger, more agile, and everything else that this 72 year old isn't. Besides, he is a Chevy electrical mechanic so I had full confidence in his ability. The problem was he couldn't assist for a couple of weeks because he just bought a new motor home (4 wheel drive no less, didn't know they existed) and was in the process of modifying everything.
Being an impatient person I wanted to see if I could do the work myself. I peeked in through the steps and could see the components and could get my hands in there but it would be tight. If only the steps were extended. Well, turns out you can remove the pin that connects the motor linkage to the steps and happy days, the steps extended free of the motor hardware.
Now I could easily get to things to measure voltages and also check to see if the steps were binding at all. I bought a wire piercing tool from Amazon which allows you to poke a wire and take a reading. I didn't know these things existed and they are indeed a life saver.
Anyway, I took measurements on the 12 volt supply voltage and verified the magnetic door switch worked. When I measured the voltage right across the motor I got nothing. Made me thing the controller was bad. Then I realized I had the switch set to keep the steps extended which takes the motor out of the equation (unless you start your engine).
With the switch in the position that make the steps go in and out with door usage I now was seeing voltage on the motor. It was only a brief pulse but at least it was there. I had read a bulletin on what is called a locked rotor state where the electronics don't work because the motor has been locked out due to a bind in the system. Unfortunately the fix mentioned did not help my problem.
Since I could access everything with the steps extended I decided to pull the motor. It came out pretty easily and when I cycled the door the motor worked just fine. Reconnecting the linkage allowed normal linkage operation (steps were still disconnected).
I believe the source of my problem was a jammed motor/gear due to me short cycling the steps. What I had done was partially open the door and then close it right away. The steps were only slightly extended when they were forced back into the retracted position. The motor would have hit it harder than normal before it timed out. I think it simply bound things up some where the control motor current sensing circuit thought the motor was in a locked state.
I decided to replace the motor as I found a lot of people had motor problems. Swapped in the new motor, reconnected the step hardware to the motor linkage, and cycled the door many times. Working like a champ.
Boy am I long winded! I am attaching some docs that will help anyone with a step problem (provided they have the Kwikee brand of steps) to help isolate the problem.
My recommendations are to first disconnect the steps from the linkage. You remove a carter pin and drive a linkage pin out with a hammer. This allows easy access plus makes it safer in the event the motor energizes while your arms are inside the housing. Take a voltage reading across the motor first to see if the controller is trying to energize it. If voltage is there, the problem most likely is in the motor/gearbox. Remember to try both positions of the step switch. If there is no voltage at all, the problem could be in the supply voltage, door switch, controller, or whatever. Just a suggestion.
Kwikee Part IDs
- shows all models to help identify your model and has part numbers of components.
Kwikee Locked Rotor State Test
- describes how to fix a locked rotor condition.
Step Service Manual 1,2,3,4
- Kwikee service manual for their line of steps. Had to split it into pieces due to forum size limits.
Jayco 12 Volt Chassis
- shows how the steps may be wired into your rig (this is for my 2017 Ford E450 chassis).
- picture of the wire piercers that are great to take measurements).
- picture of the cables I used to connect the wire piercers to my test meter.