Replacing Electric Step Motor

As luck would have it, it's not been simple. The new motor has a little lip on it that puts it at enough of an angle to where the bolt holes don't line up. That lip keeps it from laying flush. I could grind it down, but I'm contacting the seller first. Then a ground wire got pulled loose from the control module, so I get to buy a new one. The control module is sealed so I guess it's non repairable. Oh gee has this been fun.

Just retracted ours, older Kwikee two-step from around 2002. Matches manual 875. Steps retracted, looks like this


The blue wire tie is through the cotter pin that secures the pin connecting motor assembly to step linkage. I really thought that the motor was covered when the steps were retracted, but I can get at motor and linkage. Maybe not the two-wire connector to the motor, didn't look for that. One worry off the table, at least accessing the motor. FINDING one at anything under three figures, not so sure...

D.E.Bishop wrote:
I don't think it is anywhere near impossible with the steps retracted. Remember I suggested that the entire IGML assembly be removed at one time, not the motor, that is more difficult with the steps retracted. With the step fully extended, the pressure on the linkage increases the difficulty in removing the both the IGML and the motor itself. I have replaced the cotter key with a hairpin clip as it is much easier to remove. If the block or jackstand holding the step open it is not likely to retract when the power is reconnected and it can be done without being on your back under the steps or the RV. That is very easy to do.

ALL steps, to replace the motor is easiest with the steps extended. Now, with the steps fully extended, you can get to the 3 motor mount bolts, but as you stated, the linkage will make it difficult for the motor to release. What I do, is, I extend the steps. While underneath and CLEAR from the step assbly I access the 4 wire main step harness at the step. I have someone close the door and just as the step starts to retract. I disconnect the 4 wire step harness. THAT points the steps in a neutral position with no pressure on the mechanism. You then replace the motor. Connect the 4 wire harness and then operate the steps a few times to get the memory sequence back. If the steps will not retract due to the motor failure, you can then loosen the 4 transmission mount plate 7/16" nuts. That usually causes the mechanism to relax enough to get the motor to drop. Doug

I don't think it is anywhere near impossible with the steps retracted. Remember I suggested that the entire IGML assembly be removed at one time, not the motor, that is more difficult with the steps retracted. With the step fully extended, the pressure on the linkage increases the difficulty in removing the both the IGML and the motor itself. I have replaced the cotter key with a hairpin clip as it is much easier to remove. If the block or jackstand holding the step open it is not likely to retract when the power is reconnected and it can be done without being on your back under the steps or the RV. That is very easy to do.

And while the motor is off the steps should swing in and out totally freely. No resistance.
If not, lube appropriately.

I wonder if motor access varies with the make/model of the steps. The common answer is it about won't come apart if the motor fails retracted.

But when you get it all reassembled and restore power, the step will figure out what it wants to do. The Kwikee steps with that black logic box, figure out what to do from the input it gets. Then it looks at the electrical load on the motor. It assumes that high load means the step has gone where it needs to do, and takes the power off the motor right then. That makes it important to have the whole step assembly well lubed so it won't quit part way. Also means that if it hits an obstacle, it doesn't struggle to push through it. Knowing that, I don't fret if the door opens, step deploys, and gets stopped on a high lawn, even a curb, next the coach. Pretty slick setup. Just expensive parts.

When I last worked on ours, it was the "safety clutch" inside the large gear, the one driven by the worm on the motor armature. It's there to slip if somebody gets caught in a power car window. Not needed on a Kwikee step because of that power sensing. Anyhow, I put a Hairpin Clip ("Hitch Pin Clip?") into that solid pin connecting motor arm to step linkage. One of these Hoping I could reach in and pull that to get started working the pin it retains out in event of step failure in the retract position. Haven't tested that yet. Will try to remember to look next time I'm under there. If it looks helpful, maybe with a wire "extender" to grab it with, I'll get back here with it.

Doint it with the steps retracted would be next to impossible

however technically.. Matters not.. Full in, Full out mid way does not matter. No sensors on the motor.

Thank you all for the information. I wasn't sure if the motor itself had a mode to where it has a stopping point in the extended or retracted position, but I guess it just spins until the step gets to where it needs to be. Thanks again.

MrWizard wrote:
steps have enough torque to eat your fingers

It can take that and more!

When you plug it in when finished make sure to be on the back side of it and clear. It may retract or extend. That's when the disconnected battery could be a great idea! I've had someone open the door while working on steps; suprise!!:E

I have found that it is easiest to hold the steps up with the steps retracted and a ratchet strap around the steps to prevent them from trying to open. Disconnect the two wire motor cable. Disconnecting the battery too is okay but it's like wearing a belt and suspenders to hold your pants up. Then remove the four 1/4-20 cap screws that hold the IMGL in place. Then release the strap and using a piece of 2X4, block the steps up in the fully extended position or I use a jack stand.

Now you can release the cotter key in the linkage clevis pin and drop the entire IMGL assembly in one piece and take it to your work bench. It may take ten minutes longer to actually R&R the unit but it is worth it to be working on your bench to R&R the motor and for checking the grease in the gear box than laying on your back working upside down.

Cap screw sizes may have changed to metric and are now a 6mm 1.0 capscrew