geoff Posted March 24, 2009 Share Posted March 24, 2009 The omni step on my 54 Bessacarr 425 operates normally on the manual switch but will not retract automatically when the ignition is switched on. I have checked all the fuses located on the dash, and also those in the two fuses and relay boxes that are mounted in the engine compartment and believe the problem to be a faulty relay or a hidden fuse. Can anyone tell me the location of the hidden fuse or relay ? Link to comment Share on other sites More sharing options...
davenewellhome Posted March 24, 2009 Share Posted March 24, 2009 Under the bonnet behind the centrally mounted black plastic box which is secured with two six mm nuts. Once removed you will probably find the fuses for the step, fridge and split charge circuit. D. Link to comment Share on other sites More sharing options...
geoff Posted March 24, 2009 Author Share Posted March 24, 2009 Hi Dave, Those fuses have been checked and are ok so I guess it must be a faulty relay. Is there a quick way to determine which is the relevant relay? Link to comment Share on other sites More sharing options...
davenewellhome Posted March 25, 2009 Share Posted March 25, 2009 Hi Geoff, from memory (so I may be mistaken) its under the same cover near to the fuses along with the split charge relay. Check with a voltmeter, the split charge relay will have engine battery voltage on one pin and leisure battery voltage on the opposite pin (these are the two heavier wires) the other relay should only have engine battery voltage on one pin and nothing on the other till the engine is started, alternator D+ feed is usually a thin blue wire but don't hold me to that. D. Link to comment Share on other sites More sharing options...
geoff Posted March 25, 2009 Author Share Posted March 25, 2009 Back to square one Dave. Checked out all the fuses and relays in that box and they are all ok, the step still works o the internal rocker switch even whenthe engine is running so I am wondering if there is another relay or fuse near to the step or the rocker switch? Link to comment Share on other sites More sharing options...
trackerman Posted March 25, 2009 Share Posted March 25, 2009 I would put my money on the relay and fuse being OK. I have the Omnistep on my Autotrail Tracker and frequently have the symptoms that you describe. The problem is with the built-in switch on the step itself, which gets stuck in the "closed" position due to to all of the c**p and water thrown up from the raod - this means that the circuitry "thinks" that the step is retracted. With the step out, look on the front face of the step housing for a small black rectangulat plate - this is a switch which is probably stuck in the "in" position - give it a good clean with WD40 (other brands are available!) and puggle it until it becomes free, continue to spray and clean it until it operates freely. You should now find that the step will retract automatically when the ignition is turned on. I suggest that you clean this switch every few months otherwise the same thing will happen regularly. Regards Stuart Link to comment Share on other sites More sharing options...
geoff Posted March 25, 2009 Author Share Posted March 25, 2009 Sounds good to me.My last trip was a week in Snowdonia at Xmas and there was a hell of a lot of ***** flying around. I.ll give it a try tomorrowand let you know how it goes Link to comment Share on other sites More sharing options...
Keithl Posted March 25, 2009 Share Posted March 25, 2009 Geoff, If that fixes it then it might be worth making up a mudflap or something similar to try and keep it clean in the future. Keith. Link to comment Share on other sites More sharing options...
davenewellhome Posted March 26, 2009 Share Posted March 26, 2009 Geoff, its also worth checking that your split charge circuit is working as well because it might be the D+ signal from the alternator that's failed due to a bad connection. I've seen the connection made with Scotchlocs before now and they are notoriously unreliable. D. Link to comment Share on other sites More sharing options...
geoff Posted March 26, 2009 Author Share Posted March 26, 2009 Tried the switch operated by the step, and it seems to be OK. I thought it may be a power cut off but when I pressed it it didnt stop the step retracting. Whats the purpose of this switch, and could this be the cause of my problem ? I also found another relay which was hidden in the fridge compartment and accessed it by removing the sink. Tested it on the bench and it functioned OK. Dave, not sure where to look for the D+ connection, but I did check out the other relays, swapped them over etc and the fridge and step (manual ) still functioned. Link to comment Share on other sites More sharing options...
bob b Posted March 26, 2009 Share Posted March 26, 2009 Did you check the fuses visually or with a meter Geoff ? Sometimes they look ok but have actually blown. Link to comment Share on other sites More sharing options...
geoff Posted March 26, 2009 Author Share Posted March 26, 2009 Good point Bob. Back to square one tomorrow and double check with meter :'( Geoff Link to comment Share on other sites More sharing options...
trackerman Posted March 26, 2009 Share Posted March 26, 2009 In very simple terms, when you turn your ignition on there is a direct 12V supply routed to the step motor via the in-built step switch - if the step is out the in-built switch contacts are closed and the step is retracted by its motor until it depresses the in-built switch, whose contacts are then opened, thus removing the 12v supply from the step motor. When the ignition is turned off there is no direct 12v supply to the step motor and therefore the in-built step switch does not function. Under these conditions the step is only activated by the normal control switch by the door. I have the circuit diagram for my Tracker which I am happy to e-mil to you if this would help. Stuart Link to comment Share on other sites More sharing options...
geoff Posted March 27, 2009 Author Share Posted March 27, 2009 UPDATE Checked fuses and relays with meter, still got the same problem. Even when the engine is running the manual switch still operates the steps up and down, but, The fridge 12v comes on as normal, and the lights will not function. All I can think of now is whether there is a bad connection to or from the step switch. Looks like I'll have to take the motor off to get to it and hope its a straightforward job replacing it :-( Link to comment Share on other sites More sharing options...
geoff Posted April 16, 2009 Author Share Posted April 16, 2009 SUCCESS AT LAST It appears that my problem was caused by an bad earth connection from the cut off swich mounted on the motor housing. Although this item was checked early on and seemed OK, it was an intermittent fault that caused me all the aggro. I tried to access the switch by removing the two screws retaining the motor cover.Because the cover did not easily come off I took the complete step off and lo and behold .... the cover came straight off !!!!!!!!!!!!!!!!!! The switch was removed, cleaned up, vaseline'd etc and now works OK Many thanks to Dave Newell whose emails kept me on the right track Link to comment Share on other sites More sharing options...
Clive Posted April 16, 2009 Share Posted April 16, 2009 This may help you diagnose the fault. http://www.motts.org/Omnistep.htm C. Link to comment Share on other sites More sharing options...
geoff Posted April 17, 2009 Author Share Posted April 17, 2009 Clive Where were you when I started this thread? You wanted me to figure it all out for myself did'nt you ? :'( Link to comment Share on other sites More sharing options...
Clive Posted April 17, 2009 Share Posted April 17, 2009 Sorry mate, We have couple of relations over from Houston staying so my attention has been elsewhere. Hope it helped though. A similar question came up from an MMM reader some while back so my answer was already prepared and has been published in Interchange. Regards C. Link to comment Share on other sites More sharing options...
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