No 12v power but hookup working fine, Please help!!

[ARG]

Hi there fellow campers, I'm having a little (I hope) problem with my Bongo electrics. I'm a real novice and low on funds so i'm trying to find out as much as I can on the setup. So any info/help would be REALLY appreciated. I'll try and make it as easy as possible to explain and hope I don't leave to much out (because of my limited knowledge). Ok here goes!! I Have my water pump, fridge, and lights in the back of the van that can be run from my main battery, my leisure battery or by hook up. All I have to do is switch a button over on my ZIG unit to decided which battery to use. If a hook up is being used it will overrule both of these. If my leisure battery has been on all day and is dead all I would need to do is start up the engine and the power dial on the ZIG unit would atomically go up to full power and the electrics would all be working (even when it was still switched to use the leisure battery which is dead). Am I right in thinking it would now be running from the engine/alternator? But a few months ago this all went wrong and just stopped working. I used the leisure batt for my fridge for a good few hours and, as expected, when I came back it was dead but this time when I started the van up NOTHING, the dial never moved and was still on red. So I went into the back and switched the unit over to use the main battery (which I know was fine as it had just stated the van) but still nothing. I have used the hook up cable and all is well when I use the hook up. From what I can see, the hook up cable goes to a white box with a clear plastic cover with a trip/cut-off switch and two little switches labelled "sockets" and "charger" am I right in thinking this is a transformer? It will charge my leisure batt and give me power to my two 3pin house hold type sockets when the hook up is in and switched on. So all seems to work fine with my hook up but when I try to use the 12v batts nothing works. I've checked my leisure batt and it is fully charged. I find this a little odd as I thought it would be dead from the last time I ran the fridge, but maybe the problem happened soon after I left the fridge on a didn't drain it or maybe somehow its been charged thought the alternator(?) Does anyone have any ideas??? Could it just be a blown fuse? If you need anymore info I will TRY to give it. Many thanks in advance.

[francophile1947]

Welcome to the madhouse and well done for putting your location in your profile (lots don't and it really helps us to help you )
Sorry, I can't help you as I haven't got a Zig unit, but I'm sure some knowledgeable person will be along shortly

[Neil954]

Welcome aboard arg.
Not wishing to teach one to suck eggs but have you checked all relevant fuses, I had a problem with my main battery not so long ago and after days of ripping my hair out it turned out to be a blown fuse.
Just a thought.

[g8dhe]

Chances are that you have blown one or more fuses.

The fuses concerned are the ones leading from the Starter Battery to the ZIG unit and also possibly the fuse between the Alternator/Starter Battery and the Leisure battery.

Quite often these are in-line fuses under the bonnet and should be mounted quite close the relevant battery. In all there should be 4 fuses one from the Starter B. to the ZIG unit, one from the Leisure B. to the ZIG unit, and a pair one close to each battery that are linked by your charging relay. I would look at each battery and trace any additional wires away from the battery, there should be at least two extra wires from each battery that will lead to the 4 fuses. When the Leisure B. has been completely flattened then the surge of charging current when the charge relay (also often known as a Voltage sensitive Relay - VSR) first closes can blow the fuse. Likewise its possible that there WAS (not now as the ZIG Charger obviously still works) a fault down line of the batteries and maybe after the ZIG unit that has also blown the fuses. Have a check round all these fuses and see what's blown, if the fuses in the charging circuit have blown then try replacing them and then start the Bongo but DON'T rev the engine let it put some charge in both the batteries slowly before putting your foot down The other way is once the fuses have been replaced leave the ZIG unit charging the leisure battery overnight that will prevent the surge current that can blow the charging fuses when you first start.

[Evil Edna]

Funny that! I'm the better half of spherical visions - he has spent all afternoon mumbling about blown fuses!!! There speaks the voice of experience!

[g8dhe]

Ho yes
Just don't put 4mm self-tapping screws into a 15mm copper pipe and expect the two wires inside to be out of reach of the screws, they homed in like missiles, went thru they layer of heat shrink tubing giving a bit of extra protection, and shorted them out a treat

[ARG]

Thanks for the fast replies. Ill look at the fuses in the morning. I don't really know what i'm looking for but i'll have a look at the wires coming from the main b. I've not seen any fuses on the wires from the leisure b. On the Zig unit there are 3 fuses below each switch that i've checked and they are all ok. There's a small round white plastic disk that i've taken the top of off but i don't really know what this is doing. Alot of the wires go into it then back out again in different orders to the Zig unit. Like I said i'm clueless to most of this so any more thoughts or info would be great. Thanks again

[Gaza69]

hi, i have the same set up as yourself and also had the same problem last year. i looked everywhere to try and figure it out, also had the unit out and pretty much rewired it. but still no joy. so i admitted defeat and when on a weekend hol anyway, running off the main batt. Spent all weekend worrying over power, then on the sunday before setting off decided to check the water, as it turned out as similar posts above say there are many fuses between the unit and leisure batt, the little bugger i wanted was located literaly under the coolent but sightly tucked behind the batt itself out of view.

Not sure if yours is the same but mine was a 15amp fuse.

[ARG]

Sorry for the late update but been away in the bongo. It was down to the fuse just after the main batt. A white 25amp, As easy as that Can't work out why it went as i've left the fridge on and run the L' batt down to dead pleny of times. I've done it a few times when away this week and it's not blown again . But doesn't mean i'm not taking a few spares with me just incase. Any ideas why/how it went in the first place?? Thanks people for all the help, and at least I have a better understanding on how it works and looks.

[g8dhe]

The chances are that fuse is the one that charges the Leisure battery from the Alternator/ Starter battery, hence with the L/B flat then there is a large inrush of current when you first start, after a few times the fuse will blow - I also suspect that your NOT using a Voltage Sensitive Relay but one switched from the Ignition key (thats OK but be aware of it, if you leave the Ignition on then you are actually using both batteries in parallel). If you flatten the L/B a lot then get ready to replace it, they won't last forever if you continually flatten them completely.