Community Forums

barmcd · 03-23-2022, 02:01 PM

With the coach running, the step extends or retracts when the door is opened and closed. With the ignition off, the step won't extend. I've tried it with the step switch in the on of off position and it works the same both ways.

They are a Kwikee single step, Nr. 35, which is a pre IMGL. The controller P/N is 909506000 and the motor P/N is Lippert 379608. I replaced the original motor about 4 years ago.

I think the fact the door operates normally when the ignition is on, eliminates the door magnets. I have a schematic and its not much help since the logic is contained in the control unit. My plan is to check all the fuses, clean the grounds, and connectors and hope that clears it up. I have the Kwikee trouble shooting guide, but I really don't like the way it works since it takes you through a test procedure and doesn't list problems and possible solutions.

Anyone have a similar issue?

I managed to work around it by opening the door before turning the ignition off. The step stays out when the key is turned off.

HarryStone · 03-23-2022, 08:12 PM

The troubleshooting steps will take you through each step in determining where it fails. There will only be 4 solutions, wiring/power, door switch, controller or motor. The troubleshooting will help you determine which one it is. I'd suggest, off the top of my head, that it could be the over-ride switch. It's supposed to lock out the step control (by removing control voltage to the step) If the switch is not passing voltage, it won't move, except to retract/extend with the key on. You can check that easily by testing for 12 VDC on the white wire, at the 4 pin connector.

barmcd · 03-23-2022, 08:57 PM

Quote:

Originally Posted by HarryStone

The troubleshooting steps will take you through each step in determining where it fails. There will only be 4 solutions, wiring/power, door switch, controller or motor. The troubleshooting will help you determine which one it is. I'd suggest, off the top of my head, that it could be the over-ride switch. It's supposed to lock out the step control (by removing control voltage to the step) If the switch is not passing voltage, it won't move, except to retract/extend with the key on. You can check that easily by testing for 12 VDC on the white wire, at the 4 pin connector.

Thanks for the suggestion. I found a Kwikee Step troubleshooting flow chart that is a lot easier to use than their testing procedures, but I wish there was a circuit description some place. Just so I understand what I'm looking at, the Step Switch must be closed when in the off position to pass 12 VDC from the 5 amp fuse to the white wire of the 4 pin connector. Is that right? Do you have any idea where that fuse might be located?

barmcd · 03-23-2022, 10:33 PM

I think I have it now. I never paid much attention to the Step Switch in the years we've owned the coach!

There should be 12 VDC on the white wire when the step switch is in the "ON" position and the step should extend and retract with the door opening and closing. In the "OFF" position the wire should have 0 VDC and the step should extend and stay in that position regardless of the door position.

From the owners manual.

Operating the Entry Step:
1. With the entrance door open, turn the step switch on.
2. Close the door. The step should retract and lock in the UP position. The step
light will remain on.
3. Open the door. The step should extend and lock in the “down” position with the under step light on. The step will retract when the door is closed.
4. The step is equipped with a power switch. When the switch is turned off, the step should remain in the extended position with the door closed and the under step light off.

The troubleshooting tree from the Kwikee manual.

HarryStone · 03-23-2022, 11:32 PM

On my coach, the fuse is in the bcc. No idea on yours sorry.

barmcd · 03-24-2022, 10:08 AM

Got the step fixed - it turns out I had no domestic 12V. As soon as I restored that, the step started working as it should with the ignition turned off. I have an issue in the back run bay that I need to fix, I'll start another thread for that.

I don't fully understand that circuit yet, but it looks like it uses the chassis 12V for operation when the key is on and domestic 12V when the key is off. Does that sound plausible?

HarryStone · 03-24-2022, 04:48 PM

You have a yellow wire that comes from the ignition switch, a red wire that provides power to move the step, and a white wire that is from the step switch inside the door. I'm guessing the white wire power comes from the coach battery, and the yellow and red wires are getting their power from the chassis battery.

Iceclimber · 03-24-2022, 05:41 PM

Are you sure your chassis batteries are ok ? No chassis battery, no step. Also a typical culprit here is a bad ground.

barmcd · 03-24-2022, 06:19 PM

Quote:

Originally Posted by HarryStone

You have a yellow wire that comes from the ignition switch, a red wire that provides power to move the step, and a white wire that is from the step switch inside the door. I'm guessing the white wire power comes from the coach battery, and the yellow and red wires are getting their power from the chassis battery.

That's what I'm thinking. I'm going to do a little experimenting to see if I can verify that.

barmcd · 03-24-2022, 06:21 PM

Quote:

Originally Posted by Iceclimber

Are you sure your chassis batteries are ok ? No chassis battery, no step. Also a typical culprit here is a bad ground.

The chassis battery is fine, I started and drove the coach and when I arrived and turned the key off, the step wouldn't extend. The step will extend with the key on and the engine off if I open the door.

barmcd · 03-27-2022, 01:45 PM

I went through the Kwikee troubleshooting flow chart and the step is working as designed. The issue definitely was the low voltage on the domestic battery bank. I also measured the voltages on the 4 pin connector as the step operated through its different modes.

Harry pretty much nailed the step operation in post #7 above.

1. If the IGNITION in the ON position, the step extends or retracts every time the door is opened or closed regardless of the position of the STEP switch.

2. If the IGNITION is off and the STEP switch is on, the step extends or retracts every time the door is opened or closed.

3. If the IGNITION and the STEP switch are off, the step extends and will not retract until the the IGNITION or STEP switch are turned on.

4. The STEP switch can also be used to keep the step from extending when the IGNITION switch is turned off.

The red wire provides power to move the step, the white wire changes door operation, and the yellow wire tells the step controller the ignition is on and the brown wire tells the controller if the door is open or closed.

The RED, WHITE and YELLOW wires all get power from the chassis battery in my coach. In fact, the RED and WHITE wires both get 12V from the same mini-breaker in the rear run bay. The YELLOW wire gets 12V from a breaker labeled STEP IGN in the front run bay. The BROWN wire supplies a ground which the controller uses to determine if the front door is open or closed.

The RED wire has to have 12V on it for the step to move in any condition.

The WHITE wire only has 12V on it when the STEP switch is in the ON position.

The YELLOW wire has 12V on it when the coach IGNITION switch is in the on position.

The BROWN wire indicates whether the door is open or closed. When the door is closed, the BROWN wire provides a ground for the 12V on the RED wire.