12v problems when hooked up

Page 1 of 4 1, 2, 3, 4  Next

View previous topic View next topic Go down

12v problems when hooked up

Post by stuart90 on Sun Apr 16, 2017 1:09 pm

My Legend GL has an mc2000 zig unit. When hooked up the fridge works until I turn the 12v switch on. By day two at a camp site the 12v would stop working completely. I have disconected 12v from the fridge which has not helped. I have connected a charger to the leisure battery to increase the charge when hooked up as it was insufficient from the internal charger. By the second day of camping the mains power light on the zig unit goes off from time to time. When I switch on the 12v on hookup the leisure battery drops from about 12.7 to 10.7 straight away and the fridge stops working. The fridge wont work on 12v.
I have had an auto electrician take a look, he checked the earth cable but was none the wiser. No fuses blow. There is a light working off mains which continues to work when hooked up. Any help would be appreciated.
Stuart confused3
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by dbroada on Sun Apr 16, 2017 1:58 pm

I can't commeńt on the van as I am not familiar with it but I will say a 3 way fridge should not be used on just the battery. They typically draw btween 8 &10 amps and will kill a battery very quickly. They are fine when the van engine is running and usually have a relay to ensure that is the case.

_________________
Dave
avatar
dbroada
Donator
Donator

Male

Posts : 1517
Joined : 2015-10-25
Member Age : 63
Location : Surrey
Auto-Sleeper : Nuevo EK (Fiat)
Vehicle Year : 2016

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by daisy mae on Sun Apr 16, 2017 2:24 pm

My fridge only works on 12volt when travelling, i.e. ignition on, mains electric or gas when not, I thought all the fridges worked this way, with 30years of having caravans now motor home fridges  I haven`t found it any different, I stand corrected on this if this isn`t the case.
avatar
daisy mae
Donator
Donator

Female

Posts : 4365
Joined : 2013-02-03
Location : Leicestershire
Auto-Sleeper : Anniversary Clubman
Vehicle Year : Oct. 2003 VW 2.5 TDI

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Sun Apr 16, 2017 2:41 pm

Thank you for your replies, I should have mentioned I would never attempt to use the fridge on 12v unless travelling as this would drain the battery. When I referred to switching on the 12v on hookup I ment on the zig unit and that was simply to use water pump, toilet etc
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by brodco on Mon Apr 17, 2017 8:57 am

Hi wave

stuart90 wrote:. When I switch on the 12v on hookup the leisure battery drops from about 12.7 to 10.7 straight away

Where are you measuring the voltage? If it’s directly across the battery terminals the battery is duff.
If that sort of drop was due to the load the habitation fuse would blow instantly. If you are measuring the voltage somewhere else there is the possibility of a voltage drop in the wiring so it really does need to be measured directly on the battery.

stuart90 wrote: I have connected a charger to the leisure battery to increase the charge when hooked up as it was insufficient from the internal charger.

That’s a bit suspicious in itself. The internal charger (assuming a Zig X3 and it hasn’t been modified) is only capable of 6.5A continuous but unless you have some high current devices it should be OK.

You may have a single problem or a more than one (sometimes multiple faults lead to confusing symptoms) so I’d start with three simple checks to test each part of the system separately.

In no particular order:

1, Check that the internal charger works.

Disconnect the leisure battery, connect the hookup and check that the 12V equipment (except the fridge) works.

2, Check that the leisure battery is basically serviceable (actual capacity testing can be left until later).

With the leisure battery disconnected from the van charge it with your external charger and when you are sure it’s fully charged connect a load and check that the battery can power it for a reasonable time.

A headlamp bulb is ideal but if you haven’t got bit’s of wire and the gubbins to connect it up you could get hold of something like this:

https://www.amazon.co.uk/Accessory-Socket-Battery-Clamps-Crocodile/dp/B003SQ6U6Q

and use any 12V appliance that takes a reasonable of current, a tyre pump perhaps.

3,Check that the leisure battery is being charged when driving.

Make sure the split charge system works. Measure the battery voltage with the engine off. Start the engine and make sure the voltage climbs to around 14V.

If the problem is not obvious re-post with the results.

Brod
avatar
brodco
Member
Member

Male

Posts : 813
Joined : 2012-07-30
Member Age : 62
Location : Worthing
Auto-Sleeper : Duetto
Vehicle Year : 1997

View user profile http://www.eurotherm.co.uk/en-gb/products/

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Mon Apr 17, 2017 2:56 pm

Thank you Brod, I will follow your advice and get back to you
Stuart
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Sun Apr 23, 2017 12:28 pm

Hi Brod, sorry for the delay. I disconnected the leisure battery and the 12v works fine on hookup (which amazed me as I thought without the battery it would not work). With engine running the leisure battery charged steadily. The leisure battery appears to hold it's charge, we changed it at the end of last season.
I have a question, please excuse my very limitted knowledge of electrics but if the 12v works without the leisure battery and we are always hooked up when away with as I mentioned a battery charger connected to the leisure why would the fridge stop working?
Kind regards
Stuart
I mentioned
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by brodco on Sun Apr 23, 2017 6:45 pm

Hi  wave

stuart90 wrote: I thought without the battery it would not work

The Zig is a 12V power supply so it’s a mistake to thing of it only as a battery charger. When you are on hookup it’s supplying the van and charging the battery providing you don’t take more power than the Zig can supply. If you do take more power the battery will stop being charged and supply the extra current.

You shouldn’t need an extra charger unless you have something in the van that takes a lot of current (and if you have a better solution is to fit a higher current power supply).

stuart90 wrote:I have a question, please excuse my very limitted knowledge of electrics but if the 12v works without the leisure battery and we are always hooked up when away with as I mentioned a battery charger connected to the leisure why would the fridge stop working?

The fridge will be disconnected from the 12V supply unless the engine is running. I don’t know were it is on your particular van but somewhere there is a relay that connects 12V to the fridge when the engine starts.

The Zig won’t give enough current to power the fridge and even if you fitted a bigger power supply you wouldn’t want to use a large part of it’s capacity running the fridge.

Brod
avatar
brodco
Member
Member

Male

Posts : 813
Joined : 2012-07-30
Member Age : 62
Location : Worthing
Auto-Sleeper : Duetto
Vehicle Year : 1997

View user profile http://www.eurotherm.co.uk/en-gb/products/

Back to top Go down

Re: 12v problems when hooked up

Post by Infared on Mon Apr 24, 2017 12:42 am

If your mains light on the Zig unit is intermittent after a couple of days then that suggests to me a mains power problem especially as your fridge stops working when running on mains power (How do you know its not working?). From the checks you have already done its not a 12 V problem. I think you need to check your mains power wiring.

Ian
avatar
Infared
Member
Member

Male

Posts : 51
Joined : 2015-02-26
Member Age : 70
Location : Weston-super-Mare
Auto-Sleeper : Warwick Duo
Vehicle Year : :2011

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Mon Apr 24, 2017 10:10 am

Thank you for your replies, on our last outing I left the 12v to the fridge disconnected as I had assumed that was the problem but it made no difference. The mains supply has been from various sources but always the same result. We know the fridge stopped working when we switched 12v on the zig unit because over night the fridge warmed up and we had not moved the camper so it was still level. We also know the power source is constant because we have a light in the motorhome that works regardless of the zig unit and that continues to work.
No Brod we are happy using a couple of lights occasionally and the toilet andd water pump so no we don't need extra 12v.I added the independant charger only on the advice of an auto electrician because he said the rate of charge on hookup was quite low, although he did say he was not familiar with motorhomes.
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by -mojo- on Mon Apr 24, 2017 12:59 pm

stuart90 wrote:he did say he was not familiar with motorhomes.

I'd suggest you would be far better off using someone who does understand the electrical systems typically used in motorhomes. It's not that they are complicated, but you don't really need someone learning as they go along at your expense!

Ok, now is it fair to assume that you understand that the fridge - if it is the one originally fitted on a 1988 van - is almost certainly a 3-way fridge? So when you get to a campsite, you have to switch on the 240V mains switch on the fridge for it to work? Please don't be offended if this is just stating what is already obvious to you, but you haven't yet said anything that suggests that you understand this.
avatar
-mojo-
Member
Member

Male

Posts : 3682
Joined : 2012-08-04
Member Age : 18
Location : Southeast
Auto-Sleeper : Trooper
Vehicle Year : 2006

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Mon Apr 24, 2017 3:31 pm

Hi, I would love to book my camper in for repair but as a pensioner on limitted income I don't always have that luxury. I bought the three way fridge second hand three yers ago and fitted it myself. When I hookup at home or on a site I hookup, switch the main hookup  switch next to the drivers seat on, go to the zig mc2000 and check I have a red light indicating power and I switch the fridge to mains and it works all day every day until I switch the 12v  switch on the zig unit on. When I do that the leisure battery drops by about 2v and by the next day the fridge is warm and the power light on the zig unit goes on and off at random. I posted on the forum incase someone had had a similar problem and might be able to help.
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by brodco on Mon Apr 24, 2017 3:58 pm

Hi  wave
stuart90 wrote: I posted on the forum incase someone had had a similar problem and might be able to help.
Hang on We're getting there. think_smiley_46  Even if somebody had exactly the same problem it wouldn't necessarily be the same cause. The only way to prove what's wrong is to do some logical checks to track down the problem.
stuart90 wrote:My Legend GL has an mc2000 zig unit. When hooked up the fridge works until I turn the 12v switch
I assume (never assume) that that is the 12V switch on the fridge and with the engine off the fridge won't work anyway so I suspect the fridge is a red herring.
stuart90 wrote: There is a light working off mains which continues to work when hooked up
That seems to confirm that that mains supply to the van is OK although there could be a problem with the mains supply to power supply unit.
stuart90 wrote:My Legend GL has an mc2000 zig unit.
+ The mains power light on the zig unit goes off from time to time.
Humm  scratch head looking at the pictures on the web the MC2000 doesn't seem to have one. Can we confirm which light we're talking about?



Also it would be useful to know exactly what model of Zig power supply is fitted, X3, DCU-3 or something else altogether.

My best guess (only a guess of course) at the moment would be that the power supply stopped working for some yet unknown reason and the leisure battery went flat. Looking at the measurements it's also possible that he leisure battery is on its last legs making the problem worse.

Brod
avatar
brodco
Member
Member

Male

Posts : 813
Joined : 2012-07-30
Member Age : 62
Location : Worthing
Auto-Sleeper : Duetto
Vehicle Year : 1997

View user profile http://www.eurotherm.co.uk/en-gb/products/

Back to top Go down

Re: 12v problems when hooked up

Post by -mojo- on Mon Apr 24, 2017 4:38 pm

stuart90 wrote:I posted on the forum incase someone had had a similar problem and might be able to help.

Several people here are trying to help, but the difficulty is that your description of the problem is incomplete and ambiguous - that's why we are asking questions. Up until your last post it was not actually clear that you have a 3-way fridge, nor that you were aware that it needed to be running on 240V and not 12V while you are parked up. Now that is clearer.

It's also complicated by the fact that you have wired the fridge up yourself. We know how AutoSleepers wire up a 3-way fridge - so that the 12V element only operates when the engine is running - but we don't know that you wired it up the same way.

As Brodco says, it appears to be a problem either with the Zig charger/power supply, or the leisure battery, or both. As he says, a methodical approach to testing each of those components should track down the fault easily enough. What test equipment do you have available?
avatar
-mojo-
Member
Member

Male

Posts : 3682
Joined : 2012-08-04
Member Age : 18
Location : Southeast
Auto-Sleeper : Trooper
Vehicle Year : 2006

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by brodco on Mon Apr 24, 2017 4:49 pm

Hi wave 

Sorry I’ve just read you last post properly.

I’m a bit confused because the 12V and 240V elements on the fridge should be totally separate but a thought occurs to me that if for some reason 12V to the fridge was not being turned off when the engine is off it could explain at least some of the symptoms.

That would mean hat the leisure battery and the Zig would be powering the fridge (because the Zig doesn’t supply enough current to run the fridge by itself). When the leisure battery went flat the Zig would be left trying to power the fridge and would undoubtedly cut out. As far as I’m aware most fridges don’t have a thermostat on 12V but if the fridge was cutting in and out for some reason it would explain why the light was going on and off.

I suggest that when the engine is off you check there is no 12V on the fridge connector or completely disconnect 12V from the fridge for a while and see if it fixes the Zig problem.

Brod


P.S. I’ve just noticed that you disconnected the fridge earlier but I suggest you leave it disconnected anyway so that it doesn’t confuse the other tests. When everything else is running we can worry about the fridge if it’s still a problem.


Last edited by brodco on Mon Apr 24, 2017 5:34 pm; edited 1 time in total (Reason for editing : Added P.S.)
avatar
brodco
Member
Member

Male

Posts : 813
Joined : 2012-07-30
Member Age : 62
Location : Worthing
Auto-Sleeper : Duetto
Vehicle Year : 1997

View user profile http://www.eurotherm.co.uk/en-gb/products/

Back to top Go down

Re: 12v problems when hooked up

Post by inspiredron on Mon Apr 24, 2017 5:45 pm

stuart90 wrote:Hi, I would love to book my camper in for repair but as a pensioner on limitted income I don't always have that luxury. I bought the three way fridge second hand three yers ago and fitted it myself. When I hookup at home or on a site I hookup, switch the main hookup  switch next to the drivers seat on, go to the zig mc2000 and check I have a red light indicating power and I switch the fridge to mains and it works all day every day until I switch the 12v  switch on the zig unit on. When I do that the leisure battery drops by about 2v and by the next day the fridge is warm and the power light on the zig unit goes on and off at random. I posted on the forum incase someone had had a similar problem and might be able to help.
You have hit it Brodco!  "and fitted it myself"!
The obvious way to fit it would be to wire it to the leisure battery instead of to the alternator via a relay!  After all - it needs 12V and that is the nearest source of 12V.

Stuart:  A fridge takes about 8 to 10 amps from the 12V and, as such, MUST be connected to the main feed from the alternator via a special relay that only supplies power to it when the engine is running.  That is rather specialised wiring which must also be done with heavy gauge wire to avoid a fire risk.  It is just possible that the correct wiring and relay may already be on your vehicle if it ever had a fridge fitted.  Otherwise, judging by your posts, I suspect that you need sombeody with the right expertise to re-do the wiring for you.
Have you made any other alterations to the van wiring, either 12V or mains?  If so they could be causing the Zig problems.

Motorhome wiring is quite complex to allow charging of both vehicle and Leisure batteries from both the alternator when driving and the charger when hooked up and if you are not totally competent then you can start problems.  Sorry if I am questioning your skill but that is how it is, I am afraid.

_________________
Best wishes - Ron
avatar
inspiredron
Member
Member

Male

Posts : 1603
Joined : 2012-06-02
Member Age : 76
Location : Carshalton
Auto-Sleeper : Lancashire
Vehicle Year : 2012

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by bikeralw on Mon Apr 24, 2017 7:26 pm

avatar
bikeralw
Member
Member

Male

Posts : 1224
Joined : 2013-04-22
Member Age : 66
Location : High Peak & New Zealand.
Auto-Sleeper : Nuevo
Vehicle Year : 2004

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Tue Apr 25, 2017 10:03 am

Thank you for your input Ron but I simply took a photto of the old fridge wiring and replaced the old fridge with this one wired in the same way. In addition as mentioned previously the fridge is not connected to the 12v system so could not drain the battery. But as an after thought even if it was taking 8 to 10 amps when hooked up I have an inteligent charger(I expect you know what that is) wired to it.
Thanks Ron
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by meanchris on Tue Apr 25, 2017 11:10 am

stuart90 wrote:Thank you for your replies, on our last outing I left the 12v to the fridge disconnected as I had assumed that was the problem but it made no difference. The mains supply has been from various sources but always the same result. We know the fridge stopped working when we switched 12v on the zig unit because over night the fridge warmed up and we had not moved the camper so it was still level. We also know the power source is constant because we have a light in the motorhome that works regardless of the zig unit and that continues to work.
No Brod we are happy using a couple of lights occasionally and the toilet andd water pump so no we don't need extra 12v.I added the independant charger only on the advice of an auto electrician because he said the rate of charge on hookup was quite low, although he did say he was not familiar with motorhomes.

This only tells you that the internal 230V supply to the lamp is working.

There may be an intermittent fault in the 230V supply to the Zig unit itself, which would cause the red light on the Zig to be intermittent and it to stop charging the battery.

As a matter of interest, I have a Zig3 in my garage, from our old Exec, which would work fine until a certain set of circumstances occurred (I can't remember what they were now) and then the battery would slowly use charge. I would open the little view panel to look at the charger and see that the red light was now out.

Switching the Zig mains switch off and on, and even disconnecting the 230V supply would make no difference, the Zig would not produce 12V.

The only way to get it working again was to disconnect the 12V output with it switched off, then reconnect the 12V leads and switch it back on.

I use it as a 12V test supply now, and it has never done this again while it's been out of the van.

meanchris
Member
Member

Male

Posts : 1927
Joined : 2013-08-10
Member Age : 63
Location : North West
Auto-Sleeper : None
Vehicle Year : N/A

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by meanchris on Tue Apr 25, 2017 11:16 am

Let me describe a scenario:

There's a loose connection somewhere in your 230V system - after the supply to the 230V light, as that stays on - When you turn on the fridge in 230V mode, the load on the 230V supply causes a volt drop and the Zig unit goes into what I suspect is a fault condition similar to the one I have.

The leisure battery is then not being charged.

It has to be something like this, as your description doesn't make any other sense. (I know that it's sometimes difficult to put the symptoms in any sort of logical order, this is not an attack on your abilities).

meanchris
Member
Member

Male

Posts : 1927
Joined : 2013-08-10
Member Age : 63
Location : North West
Auto-Sleeper : None
Vehicle Year : N/A

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Tue Apr 25, 2017 3:12 pm

Thank you for your input, I will give it a try and see how it goes.
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by brodco on Tue Apr 25, 2017 3:43 pm

Hi  wave

meanchris wrote:There's a loose connection somewhere in your 230V system

Except that:
stuart90 wrote: I switch the fridge to mains and it works all day every day
So there’s enough current to run the fridge faultlessly but the extra current of the Zig on light load stops it every time. That’s remarkably consistent for a bad joint but it’s worth checking because anything’s possible.

Having said that it’s the only thing that links the fridge and the Zig if they’re wired to the same point (not allowed nowadays). I still suspect the “unknown unknown” that we haven’t found yet.

meanchris wrote:Switching the Zig mains switch off and on, and even disconnecting the 230V supply would make no difference, the Zig would not produce 12V. The only way to get it working again was to disconnect the 12V output with it switched off, then reconnect the 12V leads and switch it back on.

Just out of interest I’d almost guarantee that’s the over voltage shut down cutting in for some reason. It shuts the power supply chip down if it sees (or thinks it sees) too high a voltage on the output. As its done by a thyristor so it needs both the internal supply and the external 12V disconnected before it will reset.

Brod
avatar
brodco
Member
Member

Male

Posts : 813
Joined : 2012-07-30
Member Age : 62
Location : Worthing
Auto-Sleeper : Duetto
Vehicle Year : 1997

View user profile http://www.eurotherm.co.uk/en-gb/products/

Back to top Go down

Re: 12v problems when hooked up

Post by meanchris on Tue Apr 25, 2017 3:52 pm

All fair comments Brod, I must have missed the one about the fridge working consistently, because there's also a mention that the fridge stops working when the 12V hab switch is on.

It's either a very unusual fault or, understandably, misreported somewhere in the list of symptoms.

I suspected that my Zig problem was either an internal lockout or maybe a dry joint (though I can't see one on the PCB) but it was a good excuse to update the charger anyway, so didn't look too hard if truth be told.

meanchris
Member
Member

Male

Posts : 1927
Joined : 2013-08-10
Member Age : 63
Location : North West
Auto-Sleeper : None
Vehicle Year : N/A

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by stuart90 on Wed Apr 26, 2017 8:07 pm

Hi, I disconnected the 12v from the zig unit, (incidentally the zig unit was held in place by two odd srews so not the first time removed), I reconnected the hook up and power on. I then powered off and reconnected th 12v to the zig unit. The leisure battery was showing 1353 on hookup and dropped to 1260 when I switched the 12v on the zig unit. I left it on for a few hours with 4 lights on in the camper and the fridge on 230v. After 3 hours the battery read 1192. All that time I had the leisure battery on charge. I understand the battery may need changing but pressumably power is being drained somewhere?
avatar
stuart90
Member
Member

Male

Posts : 36
Joined : 2015-06-20
Member Age : 69
Location : Brentwood
Auto-Sleeper : Legend GL
Vehicle Year : 1988

View user profile

Back to top Go down

Re: 12v problems when hooked up

Post by meanchris on Wed Apr 26, 2017 9:37 pm

Do you have a voltmeter/multimeter?

Is it possible to read the voltage directly off the terminals on the Zig charger/PSU without the battery connected, just by pulling the spade terminal leads off the unit? (Please be ultra careful not to short the battery cables together if they're not shrouded and floating around)

It almost sounds like the Zig unit is pulling the battery volts down.

By the way, I mean the Zig charger itself, not the control panel.

Edit: Does your control panel have a green light on it that comes on when the Zig charger is switched on (at the red illuminated mains ON switch on the charger)?
If so, does the green panel light come on and go off when you switch the charger on/off?

If Brod or Mojo et al read this they may suggest more or more clear diagnostic tests to try.

meanchris
Member
Member

Male

Posts : 1927
Joined : 2013-08-10
Member Age : 63
Location : North West
Auto-Sleeper : None
Vehicle Year : N/A

View user profile

Back to top Go down

Page 1 of 4 1, 2, 3, 4  Next

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum