12V lighting circuit advice please (1 Viewer)

[paul18]

Been fixing another 12V LED light into my van, but power to that particular area just went. Makes me think its a fuse obviously, so checked with multimeter and yes, no current. However the other lights are working, ie, under hob and rear bedroom area lights, just not the front ones. Cant find a fuse thats blown from my fiddling, and manual no help. I am assuming there must be an inline fuse or another fuse box I cant find somewhere? Can anyone help please, its an 04 Ace (Swift I believe)

 

[tonka]

Any help on here ??
http://sargentshop.co.uk/epages/eshop328964.sf/en_GB/?ObjectPath=/Shops/eshop328964/Categories/TechData/"System Schematics"/"Swift Group"

This one says ACE..
Link Removed

 

[paul18]

Many thanks, but not quite, my model, Ace range not included

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[paul18]

http://assets.swiftgroup.co.uk/uplo...05 MH Tech Books/Ace MH Service Book 2005.pdf

Found this, looks about right, but can anyone help me decipher it?

 

[Chipster]

Looks like 10a fuse fed with slate coloured wire.

 

[Khizzie]

Looks like 10a fuse fed with slate coloured wire.

Yes slate coloured cable from 10amp fuse.

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[Chipster]

Drawing should really have fuse numbers.

 

[paul18]

In my fuse box, the fude in that position is a 7.5, but seems intact. I will have to have another look, i suppose i should replace with a 10

 

[Chipster]

Best way to test a fuse with multimeter on resistance.

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[Khizzie]

As a precaution test them all ,you don't know who has had a play with it in the past

 

[Bluestar]

Just as a couple of thoughts, the lights will be on a loop circuit so a poor connection in the previous unit can cause a problem, also your LED are polarity sensitive so will only work the correct way round.

 

[paul18]

Thanks, checked all that and multimeter shows no current to first device

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[Bluestar]

Ok well if your earth is ok then its back to the fuse box.
Do you have two way switching i.e. another switch by the entrance?

Good luck

 

[paul18]

No, and some of the other 12v ceiling lights work

 

[paul18]

Really struggling with this one guys. All fuses working fine and all other 12v lights working fine, just no power to or from the one from which I had already sucessfully spurred off 2 little LEDs with no problem. Any other suggestions please

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[Bluestar]

So hard when not able to see what's going. on, try a bulb and wire to test circuit rather than a meter, have had it where a poor/dry joint will give a reading but not supply a voltage under load.
Failing that its a matter of tracing the wiring back to the sauce testing as you go.

 

[paul18]

Presumably the wire goes back to the previous 12v in the loop which works fine, but short of stripping back fittings impossible to tell for sure

 

[andy63]

If I've read the post correctly and you now have no voltage to the light fitting you have taken the spurs off for your additional lights then you have to trace that supply to source... I know it's stating the obvious but can't think of much else you can do..
Ta Andy

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[Deleted34567]

Test the circuit by pos/neutral separately...
Ie..... Don't just probe it at the light fitting, probe the pos at the fitting using a neutral on the other side of the test lamp taken from chassis/battery and similarly so with the neutral.
This will eliminate either the pos or the neg and give you less to look at.
Remember LED's have polarity unlike an incandescent bulb...
Use a test lamp rather than a multimeter, a multimeter will operate on low mV where a test lamp will take more draw thus eliminating a high resistance problem.
Don't know if your system is CAN bus ? ..... If so, then it's another kettle of fish.

 

[pappajohn]

As already said, leds are polarity sensitive but the installer hasnt necessarily connected all the lights the same polarity.
Try turning the led over to chech that the wiring is correct.

Just converted to led in my caravan and half the existing lights were wired backwards.....live wire to wrong pin terminal.
A conventional halogen bulb will still work but some leds wont.

 

[paul18]

It was all working fine when I tested the new light, before installing it, afterwords no power at the source light which was also working fine, nothing else has changed

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[Deleted34567]

Have you power on positive pin at light fitting ?
Have you neutral on pin at light fitting.
You need to test those with a pos/neutral that is definite.
If no continuity on either pin (unlikely) then I would look for disturbed multiplug....
If you can establish if loss is on either pos/neutral then it's easier to move on to the next step.....that is.... Testing at switch, testing if power us at another switched point, etc.

 

[andy63]

It was all working fine when I tested the new light, before installing it, afterwords no power at the source light which was also working fine, nothing else has changed

Hi Paul. . You have checked the supply to the light fitting that you have taken the further lights off???
Ie disconnected it from the fitting and checked it for a voltage...
If you have done that and there is nothing then you have to trace that supply to source...
There is nothing else you can do!!
Andy.

 

[paul18]

I cant understand why power would have gone and fuse etc is OK, nothing has changed or happened. Tracing the cables back is next to impossible without stripping out fittings

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[andy63]

I cant understand why power would have gone and fuse etc is OK, nothing has changed or happened. Tracing the cables back is next to impossible without stripping out fittings

I don't get it either...but if that's what has happened and you have checked for sure that there is now no voltage on that supply you have to find out where it comes from or abandon if everything else is working and run a new supply in...
You could do that as a lash up just to check it would work using a small battery....
Andy.

 

[paul18]

I guess so, but it was working, that what mystifies me.

 

[paul18]

As far as I can tell from the wiring diagram its the last switchable ceiling light on the rear circuit, all of which work fine, as was that one. So tracing the wires back should just go back to the previous light, which works, so nothing to gain there as no fusible links should be between them.

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[paul18]

Lashed up a temporary unfused supply as suggetsed from a 12v socket and new circuit works fine. No power from the orange/white and grey/green supply at all., yet that should come from lights before it. Dont know what else to try

 

[Deleted34567]

Lashed up a temporary unfused supply as suggetsed from a 12v socket and new circuit works fine. No power from the orange/white and grey/green supply at all., yet that should come from lights before it. Dont know what else to try

Obviously open circuit between the two.

 

[Gellyneck]

Have you tried a continuity test between the individual lights?

Oops just crossed with Jonkil!