No 12 volt unless on Hook up

[Bailey58]

Noticed when we stopped en route we have no 12v. Display dead and no pump, lights etc. I've checked all the fuses on the mains board which are all fine. Everything works on hook up so I assume there must be a fuse or a reset button somewhere. I can get to the two leisure batteries without finding anything while the engine battery is somewhat more inaccessible especially with carpets and dog in the way. I seem to remember a mass of wiring and stuff when I last saw it so is that where I should be looking? As we're on sites between now and home it can wait but any suggestions welcome.

 

[Two on Tour]

There is normally something like a 25 amp inline fuse in the cable close to the battery/batteries.

What van do you have ?

 

[Bailey58]

Bailey 740SE of 2013 vintage. There is a 25amp fuse betwwen the batteries but that is intact, a 30amp close to one of the battery terminals is heading in the general direction of the solar controller but that too is okay. I was going post a pic of the mains unit but tethering and signal is not helping and i doubt if the mains unit is the culprit.

 

[Two on Tour]

Our van has a 3 way master switch on the panel, cab battery - off - hab battery, I know a Funster (not me) that spent a morning hunting for a cable fault when somebody had switched the master to off.

 

[Neil S]

That same happened with my Bailey back in 2015
No 12 volt unless on EHU
It was on board charger was faulty

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[Landy Andy]

Sounds like your battery is completely flat. Now you need to play the game of “why”

If everything is working when plugged in to EHU then the 240v, and charger are working.

When you stopped “en route“ I assume you were driving, so then it’s odd that the engine wasn’t charging the battery, or you have a massive drain on the hab battery. How old is the hab battery?

 

[Bailey58]

Yes when we pull in for a cuppa we should of course have 12v, which now we don't. The two hab batteries were new in 2018, little used off grid since then and constantly charged at home via the solar or hook up. Can't test them until we get home for the meter which I should have brought with me!

 

[Jimbohorlicks]

They are probably flat.

 

[Landy Andy]

Ask other vans if they have a meter?

I‘d also think that putting up a couple of photos showing the batteries, solar wiring, charger on here you may get better advice. There isn’t much this lot can’t solve.

 

[Bailey58]

I'll know a bit more when I get to the vehicle battery and investigate.

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[Bailey58]

Other things get in the way after you get back home but I've now checked all fuses again which are ok. Both leisure batteries measuring 13.7v (off EHU) can't see anything to tamper with on the vehicle battery apart from connections as seen. I've exposed what I can of the mains unit and discovered what I imagine is the B2B charger but no more fuses.

The fuse shown on the battery is the link to the solar charger judging by the cable size and direction as far as I can trace it, the solar panel is blinking slowly as it always did. The 25amp between the locker and internal battery is ok.

The spaghetti wiring won't tell much bu would the 12v connection go through the mains unit and maybe something lurking inside has gone?

 

[Lenny HB]

The charger connects to the battery and all the 12v feeds are taken from the battery I would have thought the fault you describe would only happen if the batteries were totally goosed. With no EHU if you turn some 12v electrics on does the voltage on the batteries drop off a lot, if so it would point to the batteries.
That is not a B2B it's a Battery Master it just gives a trickle charge to the starter battery from the hab batteries.
You say the batteries new in 2018, with that type of charger they won't last much longer than 2 years as they will never get fully charged, I thought they stopped using those tyre of chargers over 25 years ago.

 

[Alan]

On our last van there was a reset button on the fuse closest to the leisure battery

 

[PeterE1947]

There must be a control panel where you can check water levels, turn on/off water pump
etc. On our Sergent Installation there is a panel mounted on the wall which is linked to the psu and controls the 12 volt electrical circuits. It normally turns off all 12 volt circuits when you start the engine. You have to push a button to re--enable the 12 volt circuits.

 

[Bailey58]

The charger connects to the battery and all the 12v feeds are taken from the battery I would have thought the fault you describe would only happen if the batteries were totally goosed. With no EHU if you turn some 12v electrics on does the voltage on the batteries drop off a lot, if so it would point to the batteries.
That is not a B2B it's a Battery Master it just gives a trickle charge to the starter battery from the hab batteries.
You say the batteries new in 2018, with that type of charger they won't last much longer than 2 years as they will never get fully charged, I thought they stopped using those tyre of chargers over 25 years ago.

I can't turn anything on and there's nothing showing on the display panel as it doesn't turn on. Nothing happens to the battery voltage when I throw any light switches although the voltage does increase when I start the engine. Basic system maybe but it has always charged from the solar panel and when driving. If that battery Master only supplies a charge to the vehicle battery how would the leisure batteries get a charge if there is no solar or hook up? I would have thought the BM worked the other way?

There must be a control panel where you can check water levels, turn on/off water pump
etc. On our Sergent Installation there is a panel mounted on the wall which is linked to the psu and controls the 12 volt electrical circuits. It normally turns off all 12 volt circuits when you start the engine. You have to push a button to re--enable the 12 volt circuits.

Yes the control panel operates all those facilities, state and choice of batteries, water levels, pump etc. But with the display dead there is nothing to see. The solar is still flickering away and presumably still charging.

I did read the paperwork while I was away but perhaps time for another read to see if I missed something.

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[gus-lopez]

If that battery Master only supplies a charge to the vehicle battery how would the leisure batteries get a charge if there is no solar or hook up

They don't get one then unless the engine is running.

 

[Lenny HB]

If that battery Master only supplies a charge to the vehicle battery how would the leisure batteries get a charge if there is no solar or hook up? I would have thought the BM worked the other way?

From the alternator via a split charge relay when the engine is running.

 

[Lenny HB]

Just a thought it's Brit van it will have a relay that turns the hab electrics off when the engine is running, I'm wondering if that is faulty but I still don't understand how the 12v stuff is working when on EHU.

 

[jockaneezer]

I don't think the batteries should read 13.7 volts unless they're receiving a charge from either the on-board charger or the solar, so that could mean your leisure batteries are goosed and you're just reading the solar input ? Try taking a reading after dark or cover up the panel ?

 

[Lenny HB]

That same happened with my Bailey back in 2015
No 12 volt unless on EHU
It was on board charger was faulty

Charger may have the relay inside it that turns off the hab electric when engine is running and its overiden when on EHU.

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[Bailey58]

Removed the shelf under the display panel to check and found a 1amp fuse that too is intact. Back tomorrow I think.

 

[PeterE1947]

A long shot, but have you tried resetting the display unit? I have to admit I haven't seen a system like yours but there is a post that states that the charger was "goosed" when it had the same symptoms.
Anyway, best of luck with this. Have you tried ringing Baileys? I have read somewhere in the posts that they can be very helpful.

 

[Kybod]

Just a thought it's Brit van it will have a relay that turns the hab electrics off when the engine is running, I'm wondering if that is faulty but I still don't understand how the 12v stuff is working when on EHU.

My 21 year old Elddis had exactly these faults about 3 years ago, absolutely no 12v circuit working when off hook up but absolutely fine when on mains hook up. The fault was eventually traced to the couple of quid lucas relay, which does cut out the hab circuit when the engine is running. Obviously my van has an old analogue type of wiring but something similar must be built into the modern digital circuit. Mike

 

[Bailey58]

A long shot, but have you tried resetting the display unit? I have to admit I haven't seen a system like yours but there is a post that states that the charger was "goosed" when it had the same symptoms.
Anyway, best of luck with this. Have you tried ringing Baileys? I have read somewhere in the posts that they can be very helpful.

The display is not showing any sign of life so no idea how to reset it. Yes, I think Baileys may be the next step.

Reading the manual it states the fuses for the 12v are in a cabinet or under the bed but that may be a generic statement as all the fuses they mention are across the bottom of the mains unit which is split between mains and inbuilt charger.

 

[Itsmcb]

I would remove the cover from the mains unit (with the 230v hook up cable disconnected) and check that there is 12v power coming into the controller feeding all the fuses. There will be a supply cable leaving the hab batteries via a fuse and into the controller. Either the cable is disconnected at one end or the other or the fuse has blown or the cable is broken. Just my thoughts.

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[autorouter]

Does the fusebox have a model number (on the label on the top, perhaps)?

 

[mitzimad]

i would disconnect the leisure batteries and leave for an hour then test them

 

[Bailey58]

I would remove the cover from the mains unit (with the 230v hook up cable disconnected) and check that there is 12v power coming into the controller feeding all the fuses. There will be a supply cable leaving the hab batteries via a fuse and into the controller. Either the cable is disconnected at one end or the other or the fuse has blown or the cable is broken. Just my thoughts.

There were a couple of stray wires with small bullet type female connectors but couldn't see any where obvious for them and assumed they were for a non existent extra, worth another look.

Does the fusebox have a model number (on the label on the top, perhaps)?

Yes it was (nearly) shown in # 11

A further look later today and an email to Bailey at the same time.

 

[Itsmcb]

Another thought, it's a British van so will have a relay somewhere that senses the engine running and cuts off the hab electrics (except the electric step if you have one) this may have failed.Mine has but in the position which allows the electrics to stay on, which I don't mind.

 

[Bailey58]

PROBLEM SOLVED

Opened the locker to check number one battery and found something I'd never seen before - a fuse which is out of sight normally as the mains connection covers it when in my normal kneeling position coupling and uncoupling the cable. All fingers crossed I pulled the fuse and sure enough it was blown. Replaced and all is now working.

Many thanks for all the input, now I can get back to the cricket.