swift habitation step

[jjsbc]

H i have an older swift kontiki 645 the step advances but only a small amount at a time but it does come out fully  the retract is good I have seen something about it being on a timer if so anyone know where it might be ?

Thanks for any help.

[Derek Uzzell]

I'm guessing that you have in mind this fairly recent forum thread

https://forums.outandaboutlive.co.uk/topic/60168-thule-step-problems/

That discussion revealed that some Sargent electrical systems have the capability to adjust an electric step's 'run time'.

Has your motorhome's step spontaneously suddenly started to do this, or had changes been made to the vehicle just prior to the step failing to extend in a single motion?

The issue enquired about in the earlier thread resulted from the Sargent system having been replaced and the new system's default run-time duration needing to be amended. However, I don't know if your 2007 Kon-Tiki has a Sargent system (or a Sargent system that would allow motor run-time adjustment).

[jjsbc]

No crud no stones has done this for years it's an omni step, why a switch driving a relay is required or even a timer rather than a push button is beyond me.I might try and trace the wiring if it is a timer cut it out rewire to a more sensible circuit and drive over the timer then chuck it away.I have been on many forums before but no one has an unequivocal answer.I bet the installers and repairers are watching rubbing hands waiting for me to turn up so they can overcharge me .

[Derek Uzzell]

Guidance on the wiring of older Omnisteps can be found here

https://www.motts.org/Omnistep.htm

Unless your motorhome has Sargent kit that includes step-motor run-time adjustment, there's no point looking for a timer as it won't be there.

[Alanb]

Given the description of how the step functions presented by jjsbc, I entirely agree with Derek's diagnosis.

If the OP wishes to discuss the matter further, can he please confirm that in order to extend the step, he has to make repeated pushes of a button?

Basic step operation is in reality quite simple, when the IN/OUT rocker or two button system is employed. (The rocker switch commonly used is in reality two switches.)

With the system at rest, both wires from the motor are connected to earth, (battery negative). When either end of the switch rocker is pressed, the appropriate motor wire is connected to +12V.  The step winds in, or out as required until the motor stops (stalls). The user then releases the switch, and the motor is switched off.

Thule offer a single button option, which has I believe been used by Swift, and other converters. This system, as I understand it, requires a short push of the button, to extend the step, and a second push to retract the step.  A problem is that the standard step mechanism only detects when the step is fully retracted.  It has no way of indicating that the step is fully extended.

There are two possible solutions to this problem, either detect the increase in current when the motor stalls at the end of travel, or just energise the motor for sufficient time, plus a small margin, so as to allow the step to fully extend. This is the timing referred to by Derek, as possibly requiring adjustment, In the Sargent system.

I am not aware as to which method is used in the Thule (Omnistep) system.  If it is by detecting the motor stalling current then the problem is the same as that in electrically operated windows.  It could be that in the OP's case the mechanism is oversensitive, particularly if a timing factor is included.

The basic step includes a limit switch that stays closed until the step is almost fully retracted.  In the simplest circuits, this switch is used to operate a warning light, or sounder, when the ignition is switched on, and the step is extended,  With auto retraction of the step. the same limit switch is used to operate a relay, again when the ignition is switched on (I prefer D+ live.).  This auto retract relay has its changeover contact inserted into the step orange wire, and supplies +12V to that wire when the ignition is on and the step is out..

Why use a single button system?  In my opinion its a sales gimmick, but I can see the advantage of a remotely controlled slide out, or an an automatic folding version, when trying to access the vehicle in inclement weather!  Relays are required in the more complex control systems, in order to provide an interface with the control circuitry.

I am not surprised that the OP has not found an answer on other forums. There seems to be little, or no, published information, as to the inner workings of the more elaborate control systems.  Further I am often dismayed at the poor technical quality of some advice offered on a popular forum.  However I am not willing to pay for the privelege of making corrections.

If I am in error in anything above, positive contributions should be welcome on any forum.

Alan