Swift- hab electric issue

[SM0129]

Hi

My Brother and I have upraded our van to a Swift Royal 610 1999. He has collected it and everything is great apart from the hab electrics do not work on 12v. If he plugs in the charger the hab electrics come to life, but without this he gets nothing. The battery has 12 volts, but at the switch on the panel to turn on the hab electrics it is dead. Would there be an isolater between the battery and the panel?

The van is in really good condition and looks unmolested (I have owned older vans and boats where the electrics resembled birds nests) My Brother has a good understanding of electrics and loves looking at things with his multi meter- but this has him stumped

Any suggestions would be greatly appreciated

 

[donkey]

Hi
Not sure for a 1999 van, but all late Swift vehicles have a large fuse, normally very close to the hab battery. It may be hidden behind the battery. It is normally a large orange maxi fuse.
Geoff

 

[Itsmcb]

On my van there is a brown and blue cable which runs from the battery to the control panel. If this cable is disconnected or the fuse blown near the battery the hab electrics won't work but if you are on EHU the built in battery charger (which is part of the control panel) still feeds the hab electrics.

 

[peterc10]

It could just be that your leisure battery is dead. Has he put is meter across that and measured the voltage? It should be 12.7V or so if the battery is charged.

 

[mitzimad]

have you tried with the vehicle running that would rule out fuses and switches if it works and point at battery

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[autorouter]

Does the van have a 12V power distribution box? It should have fuses and connectors for the 12V circuits. Maybe the charger is built into it, if it's not a separate charger. Some vans have a power distribution box and a separate display/control panel. These might be a well-known type as fitted in other motorhomes, so it would help if it had a make and model, or even a picture.

Some basic tests: measure the starter battery voltage with the engine stopped, and then with the engine running. If the voltage goes up, from 12 - 13V up to 14V or more then you know the alternator is charging OK.

Next, do the same for the leisure battery. Measure the leisure battery voltage with the engine stopped, and then with the engine running. The voltage should go up in a similar way.

There will be a big fuse near the leisure battery, and possibly an isolator switch as well. Check the fuse with a meter. They sometimes look OK but don't pass current. If the fuse terminals look corroded, fit a new fuse.

If that doesn't work, check that battery voltage is reaching the fuse holder - the battery terminals might be bad.

 

[Bessy765]

On some models there is a relay to disable the hab electrics when the engine is running, check this has not failed. There will be a fuse close to the hab battery usually fused at 20 amps or in older vans 10. If you check the hab bet voltage with no hook. Up, then with hook up it will tell you if charge is getting to the hab bat. If not when on hook up the charger acts as a power supply. Either the fuse will have blown or the hab battery has expired. If the hab battery is dead that may also cause the inline fuse to blow.

 

[Campervan_man]

Check your 12V earth cable isn't corroded or broken { usually attached to the rear chassis }
No earth = no circuit.

You can also test by temporarily putting a single black jump lead from the Negative leisure battery terminal to a bare metal chassis ground point.
If the 12V electrics work your 12V earth point is the problem / fault.

 

[peterc10]

On some models there is a relay to disable the hab electrics when the engine is running,

Good point. In nearly all UK built motorhomes they have the daft idea of switching all your 12V habitation electrics off if the engine is running.

 

[george w menzies]

have you tried with the vehicle running that would rule out fuses and switches if it works and point at battery

only the fridge will work with engine running the rest of habitation is isolated
check battery and conections

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[SM0129]

Thanks for your help everyone- it was the battery. I previously said it was reading 12v, but my Brother now thinks the charger may have been plugged in/ running at the time of testing it

 

[mitzimad]

if your charger is only giving you 12v thats a problem unless the battery was already fully charged

 

[autorouter]

I previously said it was reading 12v, but my Brother now thinks the charger may have been plugged in/ running at the time of testing it

You should be aware that the range of the 'resting voltage' of a battery is quite restricted. 12.8V is 100% full and 12.0V is as low as you'd normally let a battery go. So the number after the point is important.

The charger will normally bring the voltage to between 13.4 and 14.4V.

 

[68c]

Good point. In nearly all UK built motorhomes they have the daft idea of switching all your 12V habitation electrics off if the engine is running.

They do this to save having to design a proper electical system. A poorly designed and installed set up can emit stray electromagnetic fields that could play havoc with the earlier highly electronic bits in the donor van, ecu etc. Simpler to just add the ElectroMagneticCompatible relay which turns off all the habitation electrics when the engine is running.