12 Volt Electrical Problems Awning Light, Toilet and Fridge

[dataprint]

I have 3 mysterious problems that occurred with my Sterling Europa 460 at the beginning of the season which appeared at first glance to be unconnected but now I am having my doubts.
First of all my Thetford N112 fridge worked intermittently on mains and battery and then stopped, I replaced the main Power supply board and it now works again on Mains (I haven't tried the gas as I do not need it). On battery I am getting a Code 10 error which is something to do with not getting power from the car (how would it, it's not connected to the car) so I am now thinking there must be a wiring problem in the caravan.
My second problem was that the awning light does not work, I have power at the bulb (using a multimeter) and I have cleaned all the terminals and the bulb that I am using (and any others that I have tried) all work OK when connected directly to a battery. Even connecting the 2 leads at the light holder (that clearly have 12 volts at them) directly to the bulb still produces no light.
My third problem is the electric flush on my Thetford toilet which worked intermittently then stopped. New pump fitted, I have full power at the terminal, pump works OK when connected straight to the battery but not when connected to the toilet terminals which have full power.
Telephoned Sterling who said, quite rightly that if there is power going to the units and the units work when connected to another source then logic says that they should work when connected. Well I knew that anyway. Has anybody any ideas why a multimeter says that there is power that the items don't work. I've tried two multimeters by the way to eliminate them. It would seem to me that these items are connected and it must be a problem with the caravan wiring, but where do I start looking. Unfortunately being in Scotland my dealer is a 200 mile round trip so it's not practical to just pop it over to them and anyway I understand a bit about electricity and I am a pretty logical person so I cannot see what is wrong, can anyone shed any light on this for me. All other 12V electrics in the van are working perfectly. Any help gratefully received as I now think I am going mad!!

 

[Sproket]

My second problem was that the awning light does not work, I have power at the bulb (using a multimeter) and I have cleaned all the terminals and the bulb that I am using (and any others that I have tried) all work OK when connected directly to a battery. Even connecting the 2 leads at the light holder (that clearly have 12 volts at them) directly to the bulb still produces no light.
My third problem is the electric flush on my Thetford toilet which worked intermittently then stopped. New pump fitted, I have full power at the terminal, pump works OK when connected straight to the battery but not when connected to the toilet terminals which have full power.
Telephoned Sterling who said, quite rightly that if there is power going to the units and the units work when connected to another source then logic says that they should work when connected. Well I knew that anyway. Has anybody any ideas why a multimeter says that there is power that the items don't work. I've tried two multimeters by the way to eliminate them. It would seem to me that these items are connected and it must be a problem with the caravan wiring, but where do I start looking. Unfortunately being in Scotland my dealer is a 200 mile round trip so it's not practical to just pop it over to them and anyway I understand a bit about electricity and I am a pretty logical person so I cannot see what is wrong, can anyone shed any light on this for me. All other 12V electrics in the van are working perfectly. Any help gratefully received as I now think I am going mad!!

Sounds like a bad earth / wire connection......
Have you tried a seperate earth wire connected to the bulb & then back to the battery ?
Can you re-make the terminal ends to eliminate any broken wire problems ?

 

[hortimech]

On battery I am getting a Code 10 error which is something to do with not getting power from the car (how would it, it's not connected to the car) so I am now thinking there must be a wiring problem in the caravan.

There might not be a problem with the wiring, have you tried connecting the car and then testing the fridge on battery, obviously the car will have to be running.

My second problem was that the awning light does not work, I have power at the bulb (using a multimeter) and I have cleaned all the terminals and the bulb that I am using (and any others that I have tried) all work OK when connected directly to a battery. Even connecting the 2 leads at the light holder (that clearly have 12 volts at them) directly to the bulb still produces no light.
My third problem is the electric flush on my Thetford toilet which worked intermittently then stopped. New pump fitted, I have full power at the terminal, pump works OK when connected straight to the battery but not when connected to the toilet terminals which have full power.

I presume what you are measuring with the multi-meter is voltage, it may be that whilst you are showing 12 volts, there is very little amperage. Without the correct amps, the bulb will not light or just glow feebly, its a bit like if you open a tap fully, you get lots of water, but you can turn the tap until it is nearly closed, you will still get water, but only a dribble.
If your caravan is still under warranty, I would suggest contacting Sterling to ask if you can take it your nearest dealer

 

[ProfJohnL]

I have no experience of the thetford fridge, so I can't offer any pratical opinion, there, but the other faults arefairly typical of a high resistance problem somwhere in the wiring and in that regard I agree with both Sproket and Hortimech.

High resistance problems usually occur at a connection of some sort. Corrosion is a very common cause. Iit tends to affect the -ve or 0V side of the 12V systems, which in most caravans are the white wires.

It is quite possible the fridge problem may also be related to high resistcne faults on connectors or terminals

 

[dataprint]

Thanks for that, it's about the only thing I haven't tried.

 

[dataprint]

Thanks fop your reply hortimech, regretably no warranty, but I have suspected that it might be an amperage problem, so I'll get that checked out.

 

[xtrailman]

To prove its a poor connection test for voltage with the bulb or pump on, test on the same connections as the bulb or pump.
A poor connection will show a voltage drop across the bulb or pump.

 

[dataprint]

Hi Hortimech, I have managed to borrow a "proper" multimeter that can check amperage and from what I can see I am getting 7. milliamps at the offending items if I'm reading it correctly, I've no idea what it should be, do you.

 

[hortimech]

Never having actually tested a caravan, I am not sure, but you can work it out for yourself. To get how many amps you need to light up your bulb, look on the side of it, it should me marked 12v xxwatt or similar. to work out how many amps is required, use the equation amps = watts/volts, for instance, for a 21watt bulb, it would be amps=21/12, this would give you 1.75amps, this is a lot more than 7 milliamps.

 

[Jennifer2]

I have 3 mysterious problems that occurred with my Sterling Europa 460 at the beginning of the season which appeared at first glance to be unconnected but now I am having my doubts.
First of all my Thetford N112 fridge worked intermittently on mains and battery and then stopped, I replaced the main Power supply board and it now works again on Mains (I haven't tried the gas as I do not need it). On battery I am getting a Code 10 error which is something to do with not getting power from the car (how would it, it's not connected to the car) so I am now thinking there must be a wiring problem in the caravan.

The fridge should only operate on 12v when connected to the car with the engine running, so it sounds like it is operating as it should.

 

[Jennifer2]

If you have an edge connector on the PC board under the flush button, then it is possible that could be the problem. We recently had a similar problem and traced it to a poor connection in the wires in this .

 

[dataprint]

Thanks for all the advice guys, I'm still looking and I go along with the theory that it is a resistance problem so am ripping the van apart trying to trace the poor connection, if anyone knows what fuse does what on the 12v side of things (2008 Sterling Europa 460) it would be extemely helpful as Sterling Caravans, for reasons best known to themselves, do not even mention the 12 Volt fuses in the handbook or the technical handbook for the van.

 

[Jennifer2]

If you look on the Sargents website (they supply a lot of stuff to Swift) there may be some more information available, worth a look anyway.

Look under "technical data" then "Swift Group schematics".

Also, you could try requesting help on Swift's own forum.....www.swift-talk.co.uk

 

[Pinto]

We've just bought a S/H Abbey Spectrum and had problems with all the battery run lights - it was the connector behind the switch that turned the battery power on,on the control panel corroded. Can remember if we had power at the lights. My husband traced the wiring from the battery all the way to this control panel and ended up there.

 

[esdave]

Hello,
The fault you have of volts but no operation of appliances is one, I explained to many, engineers included ,is that you have volts but no current, testing with a meter will not load the system, you can have going to your appliances the full volts 13V8 14V4+ but no current / low current ,no go, so you say what can I do? ,load the circuit you are feeding, how do I do this, very easy, use a 21watt to 65watt 12 volt car bulb, depending on the current drain of your appliances.

When you do this you will find no volts/ low volts at your appliances and why, because you have high resistance /oxidisation/ poor connetions, to not allow the current to flow and energies your equipment.

http://www.leisureelectronicrepairs.co.uk
Kinds regards
David