T25/T3 leisure circuit and ZIG unit.

[Smiffo]

Hi all.

Recently purchased a 1989 2ltr Petrol Holdsworth converted transporter - my first camper - and am new to DIY repairs etc...
Long story short, after trying to work out why ZIG unit didn't work, it looks as though previous owner has cut it out, and some wires inside..!!
( We went camping for a night, and 240v input is OK, but only goes to one socket - this is easily resolved though - the RCD unit is still there )

My assumption first being that the ZIG was faulty so they cut it out - however - upon testing the leisure battery, it only gives 10v too, even after a night charge, so I assume one of the cells is dead, which made me think there may have been nothing wrong with ZIG unit after all...

Now, I managed to re-solder the ZIG unit components/wires back, and hey presto, it works...!!

Problem is, the last owner seems to have rejigged the wiring to charge the leisure battery through a relay under the driver seat ( RHD model ).
The relay seems to be a bespoke addition - it has 5 pins - which is not depicted in any Google searches for wiring diagrams, and I assume this really was used to direct current to fridge unit and to the leisure battery when engine running..!??

Upon inspection though, it would seem this relay trips when ignition is turned - not when engine running....
( Confirmed by measuring voltage across leisure battery terminals when ignition key turned but engine not running )

I see two issues with this - firstly the fridge will start to drain main battery before engine starts - secondly load is shared between both batteries if the ignition is left on without engine running - which could leave me with flat battery..??

Basically, I am considering putting ZIG unit back in to utilise the charger in it, but want some advice on the leisure battery / main battery circuit scenario too - is it a problem..?? Should I bother with a ZIG..?? Can I leave that circuit and instal the ZIG anyway for charging..??

Responses will be greatly appreciated..!!

[MidLifeCrisis]

Problem is, the last owner seems to have rejigged the wiring to charge the leisure battery through a relay under the driver seat ( RHD model ).

You don't mention which Zig unit that you have but it is common for there to be a separate relay between the main battery and the leisure battery that is triggered when the engine is running, usually referred to as a 'split charge' system (this is usually separate from the Zig unit - as you have found - Zig units usually do provide a function/switch that connects the main battery to the leisure but it is a manual switch so you have to remember to turn it on when you are driving and more importantly turn if off when you are not! So most user have the relay system installed so that the switching is done automatically).

The relay seems to be a bespoke addition - it has 5 pins - which is not depicted in any Google searches for wiring diagrams, and I assume this really was used to direct current to fridge unit and to the leisure battery when engine running..!??

If the relay has five pins then it is either the type of relay that has a pin for when it is triggered and a pin for when it is not triggered (usually referred to as the Normally-Open and Normally Closed pins) or there is a less common version when there are two Normally-Open outputs that are both turned 'on' when the relay is triggered (from your description it sounds like you may have one of these but you'd need to check to make sure that this was the case)

Upon inspection though, it would seem this relay trips when ignition is turned - not when engine running....
( Confirmed by measuring voltage across leisure battery terminals when ignition key turned but engine not running )

The relay is usually triggered by the blue/white wire (check that this is correct - no guarantees with wire colour) that runs from the alternator to the battery-charge indicator on the dash - this wire is grounded when the engine is not running and has 12v on it when the engine is on (and the alternator is providing charge). Looks like your previous owner may have got lazy and just wired it up to the ignition wire instead which has the negatives as you have described.

Basically, I am considering putting ZIG unit back in to utilise the charger in it, but want some advice on the leisure battery / main battery circuit scenario too - is it a problem..?? Should I bother with a ZIG..?? Can I leave that circuit and instal the ZIG anyway for charging..??

As you have said - the Zig is useful as a charging option when on hookup and also as a neat set of fuses and on/off switches for the leisure battery circuits. Not essential but as you have it and it (seems) to work ....

FYI - have you looked in the Wiki for 'split charge' - there is a bunch of information in there about the way that the relay is wired up and triggered.

[Smiffo]

Thanks for the prompt reply MidLifeCrisis..!

The ZIG is a CF8
After checking diagram on the relay under the seat, it would seem it has two outputs as per one of your descriptions.

It's a Durite Relay: 0-727-23.
This seems to have pins 1+3 to trigger relay ( currently connected to ignition live which I may change at a later date ) which when made live enables input via pin 2, to flow though outputs 4+8.

This makes sense now, as it sends power to the fridge, and to the leisure battery for charging via alternator.
I did look at the WIKI page, but none had a 5 pin setup as per the one I have - nevertheless, I think I have made sense of it...

I have near enough put everything back together now ( minus cable from main battery to ZIG location, as that seems to have been cut out ) and ran 240 to the ZIG location, and rewired light above sink fed from main battery to the ZIG location too.
Tonight should see me finish that off - after a brew - and if all goes well and I get a new leisure battery, I may camp out again next weekend to give it a trial run and see how it all performs!

My theory at the moment is that as long as I don't turn on the ignition for too long without the engine running, I won't need to worry about killing the starter battery - likewise, with the relay setup, I needn't worry about setting ZIG to touring to charge it when driving either!

Thanks for the reply MLC, I needed a bit of a confidence boost to be sure I was barking up the right tree - for lack of a better phrase.

I will post here to advise how it went.

Now - do you have advice on how to explain to the misses why the housework isn't done today? LOL

[CJH]

Smiffo

You seem to be on top of the system. The only thing I can add to MLC's comprehensive reply is about the trigger wire for your Durite relay. I think I'm right in saying that the conventional approach, using the alternator charging wire, stops the batteries being connected until after the van has started up and the engine is spinning fast enough that the alternator is providing a charge. The setup you've found on yours means that the batteries will be connected via that relay even during starting. That may well be OK, since the starter battery is capable of providing the cranking amps, but I can't believe it's a good thing for the leisure battery to be in the circuit at that moment. I'd say it's worth trying to replace that ignition controlled wire with the alternator wire. I found that the plug connection deep behind the fusebox was a better place to connect into it than the dashboard plug. I can probably take a snap if you struggle to find it.

[CJH]

...oh, and van work ALWAYS take precedence over housework. Mine has for the best part of the last year.

[BOXY]

Here's an Autohomes CF8 circuit diagram if it helps?

[MidLifeCrisis]

I have near enough put everything back together now ( minus cable from main battery to ZIG location, as that seems to have been cut out ) and ran 240 to the ZIG location, and rewired light above sink fed from main battery to the ZIG location too.

Just an FYI - many people don't bother to connect the Zig to the Main battery - that way there is no chance that you can drain the main by switching the wrong switch on the Zig.

[Smiffo]

OK
Finally got it all completed - including the explaining to the misses bit - and it seems to work as expected!!


MidLifer - Makes sense really thinking about it now - doing it the relay way ensures you start the engine for more juice via starter battery and you can't leave it in `Touring` on the ZIG and drain the starter battery in error with the engine off.

CJH - Thanks, I did think about that problem with the relay being active via switched live rather than alternator wire... I think I'm going to swap it tomorrow to be safe - I was going to leave it, as I intend having some major body work done on the camper next year and will probably need to pull it all out then anyway - but your concerns echo my original thoughts so I will do it to be sure.
A picture of where you find that wire would be a major help if you can supply it!!?

BOXY - Thanks for the diagram... I did find that one online, but dismissed it as it depicted a 4 pin relay - now I have the wiring sussed, your diagram is pretty much the same, but my setup has a 5pin relay to split charge leisure battery and feed fridge, rather than rely on charging from the ZIG.

I notice your diagram does have the relay fed via the starter live though too - like mine is now - and not via alternator wire as suggested in this thread. I seem to also have an extra direct permanent feed from Leisure battery to fridge for - I assume - the ignition of the gas section to cool the fridge?

Thanks again all who replied - I just needed the confidence to plough on - this was/is my first attempt at this type of work!! LOL

[CJH]

A picture of where you find that wire would be a major help if you can supply it!!?

Here you go. I've marked the blue wire that I added as the trigger for the relay. Inside that plug there's a spade connector with a 'tang' to keep it in the moulding. I happened to have some new tanged spades so I was able to include both wires, but I think it would be easy to solder a new wire to the existing spade connector. For completeness, the wiki refers to pin 11 on the dashboard connector as the place where this wire ends up. It may be a model year thing, but my 1983 van didn't have anything at position 11. I can't remember which pin it was on, but I preferred to use the plug behind the fusebox anyway.

[Smiffo]

Top man CJH - I'm on it tomorrow!!!

Thanks again, you have all been a good help.
Time for a well deserved drink, I think!?

[Smiffo]

OK....

Had another go just now to locate the `exciter` wire from the picture posted by CJH - however - it is too difficult to identify there...
None of the plugs I could find have the same colours - so - I had a little think and came up with this:

As the wire ends up on the back of the 14pin connector behind the dash anyway - to illuminate the bulb - I pulled that off and managed to see a blue wire similar to that in colour on the alternator.....
Now, this all looks different than some pictures and diagrams I could find on the net - I assume due to model differences in Petrol/Diesel etc - so I have pulled this plug off and managed to prove with a voltmeter that this indeed is showing 0v before the engine is running, and 13.7v with engine in full swing!!!

Last question on this topic: Am I ok to source my feed for split charge relay here?
( To eliminate the problem of relay tripping in and teeing onto leisure battery before engine running when ignition key turned on )

Looking at all diagrams I can find, it would seem there are no relays or anything before this - it is just a straight forward circuit...
I just want to double check before I cut it and solder some in!! LOL
P.S. I have also managed to locate the live feed currently used on the relay to switch it - luckily very close to where I need it to go - so it would be a very straight forward cut'n'solder job!!

Thanks in advance

E D I T:

I Went ahead and did this anyway - I'm a bit impatient sometimes - all seems OK, no fires!!!
Please let me know if anyone can foresee any issues with the way I have done this though.... Cheers all

[johncccc]

I also have an 1989 Holdsworth Villa and have the original handbook that was supplied when the van was converted by them. It contains a wiring diagram for all of the extra bits that are added for the conversion. I could scan it in and let you have it if this would be useful.

[Smiffo]

I also have an 1989 Holdsworth Villa and have the original handbook that was supplied when the van was converted by them. It contains a wiring diagram for all of the extra bits that are added for the conversion. I could scan it in and let you have it if this would be useful.

Thanks John - That would be really appreciated!!
I think I have it all sussed now, and everything is working as it should - I have even been out on a little run to ensure the fridge gets cold and is working - but would be good to have a copy of the documents ( perhaps stored on the WIKI ) to refer to for any future issues?

Thanks again.

[1664]

There's wiring diagrams for Holdsworths in the Wiki

[Smiffo]

There's wiring diagrams for Holdsworths in the Wiki

Evening 1664.

Quite right, there are - however - none depict the wiring I had/have.
I have managed to work it all out now, but was curious if mine is DIY style, or if it is because of the year of vehicle etc...
If someone has some for the vehicle of my year, perhaps they are different than those on the WIKI??

Basically, I have a wiring setup with 5 pin relay - not the 4 pin depicted - which isn't a big difference, but if there are concise diagrams of the example I own, it would be good to have them somewhere for others to find...

I spent two days mincing around with it - easy when you know how - but when you don't......