Technical Omnistep problem

[Neilmay]

Hi, i have a fiat ducato 2006 sundance mh. The 2 step omnistep decided to stop working about 8 months ago. Coming back from a trip the alarm started working and i had to tie up the step to stop the noise. I have replaced the switch wifh a new one, i have taken motor off and it works connected to 12v supply. Could it be fuse, relay? Fridge works ok on 12v ( some peeps have said it runs off same relay)
Where is fuse and or relay what value?
Hate electrics lol

 

[Communicator]

Hi, i have a fiat ducato 2006 sundance mh. The 2 step omnistep decided to stop working about 8 months ago. Coming back from a trip the alarm started working and i had to tie up the step to stop the noise. I have replaced the switch wifh a new one, i have taken motor off and it works connected to 12v supply. Could it be fuse, relay? Fridge works ok on 12v ( some peeps have said it runs off same relay)
Where is fuse and or relay what value?
Hate electrics lol

1. Swift Sundance? Swift do use Sargent electrics. This may be pertinent, so please confirm that MH electrics are Sargent.
2. Are these two separate events? i.e. stopping working, and then the alarm occurring at a later date.
3. Which switch have you replaced, step limit switch, or step operating switch?
4. What type of step operating switch do you have? Either up, and down button which is pressed on either end as appropriate, or a single button for raise and lower.
5. I note that you have tested the motor, but is the gear train OK?. Some MH steps can lose teeth from the gears.
6. The Sargent diagrams that I have do not show a dedicated fuse for the step. In my opinion, the lack of a dedicated fuse would be bad practice.
7. If we ignore steps that extend and retract when the vehicle is unlocked/locked, the relay associated with a step is only for automatic retraction when the engine is started.
8. In order to avoid overloading the D+ connection, Sargent connect the step relay coil, to the output of the fridge relay, but as above the step relay is only used to retract the step,automatically when the engine is started. However that does necessitate that the orange wire from the step motor is connected to the normally closed contact (87a) of the step relay, with the wire from the operating switch being connected to the common contact (30).
9. As to location of relays/fuses, on the x244 model Ducato, a common location for split charge, fridge, and step relays was under the bonnet, but step relay may be elsewhere. These locations may not apply to the later 2006 onwards x250 model. Please which model is yours? To check see first three numbers of VIN, either ZFA244....... or ZFA250....

 

[Neilmay]

Hi, i have the ZFA244 model. The switch replaced is the up and down type with a light switch by the side.
Seperate events stopped worming first then alarm at latter date.
Sargent electrics.
Cheere

 

[Communicator]

Hi, i have the ZFA244 model. The switch replaced is the up and down type with a light switch by the side.
Seperate events stopped worming first then alarm at latter date.
Sargent electrics.
Cheere

My PVC is also a 2006 244 Ducato, so will be similar under the bonnet. Also your description of the step operating switch sounds similar to mine.

May I start with the step connections. The Omnistep, whether of the raise and lower type like ypurs, or a slide out like mine, has four wires. Orange and violet for the motor, with grey, and brown for the limit switch. I will ignore the last two as your limit switch is working, as proven by the annoying buzzer.

The basic step switch is in fact two separate switches, one for IN, and the other for OUT. There should be four wires to the step switch, two to the motor, togeter with positive, and negative supply wires.

For further understanding with the switch in the normal position, both motor wires are connected to negative (earth). If the up arrow is pressed, then the orange motor wire is connected to positive, and the step retracts. Likewise if the down arrow is pressed, the violet wire is connected to positive, and the step extends.

Please see the attached section of a Sargent diagram. To confuse matters Sargent show different wire colours to Omnistep/Thule.. The motor "IN" or orange wire becomes red/blue, and the motor "OUT", or violet wire becomes red/white. More importantly the 12v supply to the step switch is shown as brown/green, which is Sargent's standard for a vehicle or starter battery supply. The orange/white wire is a Sargent standard for habitation negative or earth connections.

Action test for 12V between brown/green, and orange/white at the rear of the step switch. (A test lamp will be better than a multimeter when checking for a sound supply.)

If no supply then it is possible that a fuse has been included in the step circuit.

On the 244 Ducato a popular location for added habitation relays and fuses is under the "hood" at the rear of the engine bay. Look for wires connecting to the starter battery. If yours is a 2,8jtd, then there will be a Fiat installed relay for the flame starter under the "hood", plus three more if aircon option fitted. The two relays, and 4 way fuse block shown at the top LHS corner of the Sargent diagram, were frequently installed under the "hood", but not always. On a standard 244 Ducato there should be no visible fuses or relays in the engine bay, so any visible are possible candidates.

 

[Communicator]

@Neilmay Progress??

 

[Neilmay]

Hi, i am looking into it this weekend as i been busy in work. I have found a relay next to the alarm behind a panel by the door. Could it be this relay? How to check? This is relay pucture.

 

[Communicator]

Hi, i am looking into it this weekend as i been busy in work. I have found a relay next to the alarm behind a panel by the door. Could it be this relay? How to check? This is relay pucture.

As I am not sure when I bought my first relay, I struggle to count the number of years that I have been playing, working with, and using relays of several types, but 75 years is probably a low estimate. In that experience faulty relays have been rare.

The relay illustrated is a typical automotive changeover relay. If the alarm referred to above is the step alarm, that there the relay is probably the step auto retract relay. For a quick test check for continuity between terminals numbered 30, and 87a, which are the common (C), and nomally closed (NC) contacts respectively.

Have you confirmed that there is a supply to the operating switch? There should be 4 wires connected at the rear of the switch. Only one of these wires should have a 12V supply connected, when tested to a sound separate earth or chassis connection. If no 12V then you are looking for a blown fuse, or a loose connection in the supply.

Once you have established 12V supply is reaching the switch, check the negative connection, which the Sargent diagram shows as white/orange. This can be done by connecting a multimeter between the supply connections, but a simple 12V test lamp will give a better indication of a high resistance connection in the supply wiring.

Once you have proved the supply and return connections, you can move to the two output connections. You should be able to read 12V across these with one end of the switch pressed, with a reversed reading when the other end of the switch is pressed. If therte is no reading then the switch is suspect.

Edit. ( I meant to add that failure of the step switch is not unknown. When the step reaches the end of its travel in either direction, the motor is stalled. When releasing the switch it has to break the stalling current of the motor, which could be several times the running current. Also if the switch is held pressed too at the of the step movement, the switch itself could overheat. This could also apply when an attempt is made to operate a stuck step mechanism.)

Please note that if the relay that you mention is the step auto retract relay, then leaving it out while testing, will stop the step operating. The step motor power has to pass through the NC contacts of the relay.

I have attached a step diagram to which I have added some labels to improve clarity. Remember that the step switch is actually two switches, operated from either end of the rocker.

 

[Neilmay]

As I am not sure when I bought my first relay, I struggle to count the number of years that I have been playing, working with, and using relays of several types, but 75 years is probably a low estimate. In that experience faulty relays have been rare.

The relay illustrated is a typical automotive changeover relay. If the alarm referred to above is the step alarm, that there the relay is probably the step auto retract relay. For a quick test check for continuity between terminals numbered 30, and 87a, which are the common (C), and nomally closed (NC) contacts respectively.

Have you confirmed that there is a supply to the operating switch? There should be 4 wires connected at the rear of the switch. Only one of these wires should have a 12V supply connected, when tested to a sound separate earth or chassis connection. If no 12V then you are looking for a blown fuse, or a loose connection in the supply.

Once you have established 12V supply is reaching the switch, check the negative connection, which the Sargent diagram shows as white/orange. This can be done by connecting a multimeter between the supply connections, but a simple 12V test lamp will give a better indication of a high resistance connection in the supply wiring.

Once you have proved the supply and return connections, you can move to the two output connections. You should be able to read 12V across these with one end of the switch pressed, with a reversed reading when the other end of the switch is pressed. If therte is no reading then the switch is suspect.

Edit. ( I meant to add that failure of the step switch is not unknown. When the step reaches the end of its travel in either direction, the motor is stalled. When releasing the switch it has to break the stalling current of the motor, which could be several times the running current. Also if the switch is held pressed too at the of the step movement, the switch itself could overheat. This could also apply when an attempt is made to operate a stuck step mechanism.)

Please note that if the relay that you mention is the step auto retract relay, then leaving it out while testing, will stop the step operating. The step motor power has to pass through the NC contacts of the relay.

I have attached a step diagram to which I have added some labels to improve clarity. Remember that the step switch is actually two switches, operated from either end of the rocker.

I have tested for 12v...nothing. i have lightswitch next to step switch and that works ok. If a blown fuse? Where is it located and what rating please?

 

[Communicator]

I have tested for 12v...nothing. i have lightswitch next to step switch and that works ok. If a blown fuse? Where is it located and what rating please?

Hi Neil,

You may not think so, but you are making progress. You have established that there is no supply to the step switch. As you have Sargent electrics, then I would expect you to have found a live brown/green wire connected to the step switch.

I am attaching a Sargent diagram which is labelled as applying to your vehicle. the extract that I attached to post #4 is similar but as the actual Sundance drawing is more specific I will refer to the current attachment.

On the drawing if you locate the vehicle battery, and follow upwards through the 40A battery fuse, and then across to the left, you arrive at the lowest of a block of fuses with the top position empty. At the LHS of the bottom fuse (No. 4), a wire is slanted downwards in the diagram. Follow this wire, and it arrives at the step switch, of which no details are given. The wire colour should be brown/green. The blue table slightly to the left and up, gives fuse rating as 20A (yellow), which seems reasonable to me.

I have mentioned the 4 way fuse block previously, but be prepared to find only 3 stacked fuses, instead of a 4 way block. These are the fuses that are typically mounted under the bonnet. I cannot be precise as to the exact location, but as previously stated, under the hood at the rear of the engine bay, on the RHS inner wing above the battery, or possibly on the RHS of the bulkhead. However I think that last location is more practicable on a LHD vehicle as then no brake brake servo in that area. Another possibility is above the RHS headlight.

As fuse 4 above also connects to the control panel, you should not be able to read vehicle (starter battery) voltage on the control panel, if the fuse has failed. If control panel shows acceptable starter battery voltage, then suspect loose/corroded connection at fuse 4.

You will not find the appropriate fuse in the Fiat engine bay fusebox, of which you have posted a photo.

 

[Neilmay]

Have found fuses. One 20a blown. I replaced but still no power at switch. I

 

[Communicator]

It seems as though your fuse holder needs replacing. I have not succeeded in finding a match for yours on Ebay.

Take care not to short to chassis (earth) when handling, as there should be live connections from both batteries.

Standard safety precaution is to disconnect battery negative connections.

See if you can find a makers name, and put that in an internet search.

The diagram that I attached to post #9 shows an additional 40A fuse at the starter battery. Possibly an in line fuse, which may also have blown. Check starter (vehicle) battery voltage on the Sargent control panel. If no voltage shown, then that would suggest that 40A fuse is also blown, but in this case in addition to the step, your fridge would not work on 12V, and you split charging of the habitation (leisure) battery would not work, although the blown fuse that you have found may also have the latter effect.

Why are there three 20A fuses? Is one just a spare with no connections at the rear? If connected the fourth fuse may have been used for the step, but wires at output to step would probably be be brown/green.

For info only:
The adjacent relays will be the split charge, and fridge relays. The split charge relay will have brown/green, and brown/blue wires connected to terminals 30 & 87. The fridge relay should have distinctive red/yellow wire.

 

[Neilmay]

It seems as though your fuse holder needs replacing. I have not succeeded in finding a match for yours on Ebay.

Take care not to short to chassis (earth) when handling, as there should be live connections from both batteries.

Standard safety precaution is to disconnect battery negative connections.

See if you can find a makers name, and put that in an internet search.

The diagram that I attached to post #9 shows an additional 40A fuse at the starter battery. Possibly an in line fuse, which may also have blown. Check starter (vehicle) battery voltage on the Sargent control panel. If no voltage shown, then that would suggest that 40A fuse is also blown, but in this case in addition to the step, your fridge would not work on 12V, and you split charging of the habitation (leisure) battery would not work, although the blown fuse that you have found may also have the latter effect.

Why are there three 20A fuses? Is one just a spare with no connections at the rear? If connected the fourth fuse may have been used for the step, but wires at output to step would probably be be brown/green.

For info only:
The adjacent relays will be the split charge, and fridge relays. The split charge relay will have brown/green, and brown/blue wires connected to terminals 30 & 87. The fridge relay should have distinctive red/yellow wire.

Thanx for all the technical help. The 4th 20a fuse must be a spare as there are no connections to it in fuse holder. No makers id on holder so have ordered one similar with bottom entry for connections. I have battery voltage for both starter and leisure showing on sargent control panel so assume 40a fuses are ok. Hopefully new fuse holder will sort out issue.

 

[Communicator]

Thanx for all the technical help. The 4th 20a fuse must be a spare as there are no connections to it in fuse holder. No makers id on holder so have ordered one similar with bottom entry for connections. I have battery voltage for both starter and leisure showing on sargent control panel so assume 40a fuses are ok. Hopefully new fuse holder will sort out issue.

Good that you found a bottom entry fuse holder. It should make replacement easier. Are there two brown/green wires leading away from one of the fuses? If not, where is the step supply connected?
Hopeful point is that fuse connections may be OK when checking battery voltage, but too high a resistance for the step. Following that possibility, it could have been the cause of the fuse holder overheating, with the step trying to operate, but not managing to move. A stalled motor takes a lot more current than one that is running.
If problems not fixed by new fuse holder, do not hesitate to post again, also please report if all OK.

 

[Neilmay]

Good that you found a bottom entry fuse holder. It should make replacement easier. Are there two brown/green wires leading away from one of the fuses? If not, where is the step supply connected?
Hopeful point is that fuse connections may be OK when checking battery voltage, but too high a resistance for the step. Following that possibility, it could have been the cause of the fuse holder overheating, with the step trying to operate, but not managing to move. A stalled motor takes a lot more current than one that is running.
If problems not fixed by new fuse holder, do not hesitate to post again, also please report if all OK.

Hi, replacex fuse holder and checked fuses, all ok. Yes brown and green wires from one of the fuses. Checked the maxi fuses on both leisure and starter batteries, both ok. There is voltage getting to the 20amp fuse in holder. I checked on the control panel and it is reading power from leisure battery but not from starter battery. Still no power to step switch. Also the step alarm works ok as when engine on the alarm sounds pressing limit switch switches off. Would there be another fuse somewhere??? To the step switch?

Regards and frustrated.
Neil

 

[Communicator]

Hi, replacex fuse holder and checked fuses, all ok. Yes brown and green wires from one of the fuses. Checked the maxi fuses on both leisure and starter batteries, both ok. There is voltage getting to the 20amp fuse in holder. I checked on the control panel and it is reading power from leisure battery but not from starter battery. Still no power to step switch. Also the step alarm works ok as when engine on the alarm sounds pressing limit switch switches off. Would there be another fuse somewhere??? To the step switch?

Regards and frustrated.
Neil

Hi Neil.
Thanks for update. I am digesting it along with my Sunday lunch.
I know that the step is the most obvious symptom of the problem on your MH, but as you can not find any starter battery fuse (brown/green wires) then the fault must be between those fuses and the starter battery, which is in close proximity. Do not worry too much about the supply to the step switch, as when you find the fault, the repair will probably fix the step at the same time.

My present thinking is a problem with the 40A fuse shown at the starter battery on some Sargent diagrams. If this fuse has failed then the split charging of the habitation battery from the alternator, and the fridge 12V selection will not work. If you use EHU on sites, then you may not notice.

May I suggest, that you locate and identify the above 40A fuse. The attached diagram specifies a maxifuse, which I interpret as a maxi blade fuse. but I could be wrong.

One approach could be from the battery positive. For safety best to remove the negative first, but that means resetting the dash clock, and your radio may need a code.

The cover for the fuse board clamped to the battery positive is only clipped into place and can be removed. It is perhaps fiddly to replace, as correct alignment is essential. With the cover removed other than the big fat starter cable there should be no other cables connected to the main plate. All of the basic Fiat connections are at the rear between the battery, and bulkhead. Any other cable is probably connecting to your missing fuse.

 

[Neilmay]

Hi Neil.
Thanks for update. I am digesting it along with my Sunday lunch.
I know that the step is the most obvious symptom of the problem on your MH, but as you can not find any starter battery fuse (brown/green wires) then the fault must be between those fuses and the starter battery, which is in close proximity. Do not worry too much about the supply to the step switch, as when you find the fault, the repair will probably fix the step at the same time.

My present thinking is a problem with the 40A fuse shown at the starter battery on some Sargent diagrams. If this fuse has failed then the split charging of the habitation battery from the alternator, and the fridge 12V selection will not work. If you use EHU on sites, then you may not notice.

May I suggest, that you locate and identify the above 40A fuse. The attached diagram specifies a maxifuse, which I interpret as a maxi blade fuse. but I could be wrong.

One approach could be from the battery positive. For safety best to remove the negative first, but that means resetting the dash clock, and your radio may need a code.

The cover for the fuse board clamped to the battery positive is only clipped into place and can be removed. It is perhaps fiddly to replace, as correct alignment is essential. With the cover removed other than the big fat starter cable there should be no other cables connected to the main plate. All of the basic Fiat connections are at the rear between the battery, and bulkhead. Any other cable is probably connecting to your missing fuse.

Hi, thanx for reply. Confusion? There are brown/green wires from starter battery to 4 way fuse holder and there is voltage present. The maxi fuse is ok. Is the problem with wiring from the fuse holder to the step switch? Strange that the control panel doesnt show voltage with starter battery now as it did in the past.
Or is problem with fuse holder on positive terminal as in the diagram you sent. Sorry to be a pain.

 

[Communicator]

Hi, thanx for reply. Confusion? There are brown/green wires from starter battery to 4 way fuse holder and there is voltage present. The maxi fuse is ok. Is the problem with wiring from the fuse holder to the step switch? Strange that the control panel doesnt show voltage with starter battery now as it did in the past.
Or is problem with fuse holder on positive terminal as in the diagram you sent. Sorry to be a pain.

According to the diagrams, there should be a red wire from the starter battery positive, to maxi fuse, brown to 4 way block fuse 4, and brown/green thereafter. So converter has not adhered to diagram. You have brown/green wires leaving the 4 way block that are live at 12V,, but 12V is not present on brown/green?? wire at stap switch. (Please confirm that brown/green wire arrives at step switch, as in diagrams.
You also had partly melted fuse holders. How do the wire(s) get from the 4 way block to control panel, and step switch. How many brown/green wires are connected to the load side of fuse 4, one or two?

At this stage you have to consider the possibility of damaged wires, either trapped inside the vehicle, or abraded underneath the vehicle.

It is possible but not certain that your loss of starter battery voltage reading at the control panel is due to a resistive fault. Meter reads OK with no load. but if the step is trying to auto retract with buzzer sounding, then the voltage could collapse. (The step buzzer is powered from D+ in parallel with the step relay.)

If there is a problem with the maxi fuse holder then It would probably have signs of overheating.

 

[Neilmay]

According to the diagrams, there should be a red wire from the starter battery positive, to maxi fuse, brown to 4 way block fuse 4, and brown/green thereafter. So converter has not adhered to diagram. You have brown/green wires leaving the 4 way block that are live at 12V,, but 12V is not present on brown/green?? wire at stap switch. (Please confirm that brown/green wire arrives at step switch, as in diagrams.
You also had partly melted fuse holders. How do the wire(s) get from the 4 way block to control panel, and step switch. How many brown/green wires are connected to the load side of fuse 4, one or two?

At this stage you have to consider the possibility of damaged wires, either trapped inside the vehicle, or abraded underneath the vehicle.

It is possible but not certain that your loss of starter battery voltage reading at the control panel is due to a resistive fault. Meter reads OK with no load. but if the step is trying to auto retract with buzzer sounding, then the voltage could collapse. (The step buzzer is powered from D+ in parallel with the step relay.)

If there is a problem with the maxi fuse holder then It would probably have signs of overheating.

Hi again,
Oh me oh my.
Im not electrician, i will upload photos / videos of fuses etc etc, am i doing something wrong? I will have to get wife to take video/ take pix as im testing fuses etc, i will try this week my head is blown. U very technically knowledgeable, am thinking should i get vehicle electric techy involved? I know they can be expensive so all your help so far is appreciated. Im retired old codger lol

 

[Communicator]

Hi again,
Oh me oh my.
Im not electrician, i will upload photos / videos of fuses etc etc, am i doing something wrong? I will have to get wife to take video/ take pix as im testing fuses etc, i will try this week my head is blown. U very technically knowledgeable, am thinking should i get vehicle electric techy involved? I know they can be expensive so all your help so far is appreciated. Im retired old codger lol

And I am probably an even older retired old codger.

 

[Neilmay]

And I am probably an even older retired old codger.

Maybe so....but u know ur onions lol