strange things going on

[scottbott]

my petrol webasto seems a bit temperamental sometimes so I thought I would do a couple of things to hopefully improve things,firstly I am going to use a far thicker cable from the alternator to the battery under the rear seat and a thicker earth cable,when I disconnected the negative cable from the starter battery the ignition lights still came on!,I removed the negative cable from the webasto battery and the ignition lights went off,the starter battery and the webasto battery are not connected in any way.There is an intelligent split charger for the starter battery and the front leisure battery,the rear battery is connected up to a Ctek charger so it charges when on hookup but also charges the starter and leisure batteries even though there are no cables between the front and back.The cable for the webasto battery is fed straight from the alternator then from the battery to a separate fuse box to feed other things,is there something glaringly wrong here because I cannot figure it out

[Smiffo]

my petrol webasto seems a bit temperamental sometimes so I thought I would do a couple of things to hopefully improve things,firstly I am going to use a far thicker cable from the alternator to the battery under the rear seat and a thicker earth cable,when I disconnected the negative cable from the starter battery the ignition lights still came on!,I removed the negative cable from the webasto battery and the ignition lights went off,the starter battery and the webasto battery are not connected in any way.There is an intelligent split charger for the starter battery and the front leisure battery,the rear battery is connected up to a Ctek charger so it charges when on hookup but also charges the starter and leisure batteries even though there are no cables between the front and back.The cable for the webasto battery is fed straight from the alternator then from the battery to a separate fuse box to feed other things,is there something glaringly wrong here because I cannot figure it out

I'm trying to think here, and probably won't be a great help, but does your leisure batt connect via a relay?
Mine is and the connection is made when engine is running, but used to be like yours i.e the relay clicked as soon as ignition was switched on.
This meant both batts started the engine, so I rewired it to correct that.

What are the temperamtal conditions you get?
May be totally unrelated to symptoms?

Also, if you have no relay setup as shown in wiki pages, the pos to the alternator from each batt effectively means they are linked in parallel - I think lol

[Oldiebut goodie]

Also, if you have no relay setup as shown in wiki pages, the pos to the alternator from each batt effectively means they are linked in parallel - I think lol

That's what I understand also. Needs a voltage sensitive relay for that alternator to webasto/leisure battery feed.

[scottbott]

I have a spare relay in the garage it is from Ripaults and has the legend 2136/200 12volt and the usual connections 30,85,86,87,will I need to use a blue trigger wire from the alternator(which I have have already fitted ages ago but never used),would this relay be ok to use

[CovKid]

Yes

[scottbott]

thanks,better get out there before it is too dark

[scottbott]

just to double check.from the alternator to battery,relay,fusebox,webasto?

[Smiffo]

just to double check.from the alternator to battery,relay,fusebox,webasto?

My van is a petrol, so both batts are under each seat. ( Yours might be diesel with the batt in the engine bay. )
My starter batt is under RHD drivers seat where the relay is also situated.
From memory it goes to relay first from alternator, then different pins from relay to each battery. There is another pin for an earth, and then one for the exciter wire ( the blue wire you mentioned earlier ) then one to the fridge.

Don't quote me or hold me to the above though without checking a diagram, I would have to go and actually look to be 100% - which I can do tomorrow if needed when it's not raining and the light returns.!

If it were me I would get a wiring diagram to follow and a volt meter. It makes it so much more easier to follow and picture in your mind.
Words will make it very difficult without a diagram - that was my experience anyway.

[scottbott]

mine is a petrol,1.9DG,the battery under the rear seat is just for the webasto,the starter and leisure batteries are in the usual place,under the front seats,the split charge is an intelligent type and is between the starter and leisure batteries

[Smiffo]

mine is a petrol,1.9DG,the battery under the rear seat is just for the webasto,the starter and leisure batteries are in the usual place,under the front seats

Ah - you have 3 batteries?
That changes things a bit...

You might be better wiring it all up with just the starter, split charger and leisure batt.
Then just connecting the third batt in parallel with the leisure one?

You would get a diagram easily for that set up on the WIKI.

( This would mean you effectively have a beefier leisure setup, all through split charging system, and still retain a dedicated starter battery. )
I haven't used an intelligent charging system, so I would be venturing into guess work on that.

Let some others read this through with my suggestion. I would hate to send you on a wild goose chase.

Try this on the WIKI - it mentions intelligent charge systems:

https://club8090.co.uk/wiki/Ca ... it_charger" onclick="window.open(this.href);return false;

P.S. You didn't say what temperamental symptoms you were getting originally..
Was it just the dash staying lit when starter batt disconnected?
( If you have other symptoms, they may not be related to the battery wiring, so you may be doing this and still have your original temperamental problems. I would interperate temperamental to mean intermittent - just clarify that bit too - it's easy to convince yourself what the problem is when facing things like this. )

[Oldiebut goodie]

The 3rd battery is purely for the Webasto - separate from the leisure system. Keep it that way!
Needs the wire from the alternator to the Webasto battery cutting and the voltage sensing relay inserting there.

[Smiffo]

The 3rd battery is purely for the Webasto - separate from the leisure system. Keep it that way!
Needs the wire from the alternator to the Webasto battery cutting and the voltage sensing relay inserting there.

Thanks OBG.
This is exactly why I wanted more input - a second opinion of someone who has `been there and done it` with the charging system explained.

Out of interest - and for info for Scott too - are there any diagrams available for a 3 batt setup?
Also, what is the benefit of keeping the Webasto seperate as you describe? ( There will be one I know, but not sure what it is. )

[Oldiebut goodie]

You don't need a diagram for 3 batteries - the leisure 2 are connected in parallel is the only difference.
With the Webasto it was easier to have a dedicated battery alongside it and saved having to run cabling from the leisure in the front ( it is far better to have heaters running directly from the battery nearby rather than a long cable and/or joins which will all contribute to voltage drop as heaters need a good supply of voltage). Charging cable is short also being just the other side of the bulkhead. You will still have lights, running water, sounds even though you are cold due to having flattened the heater battery.

[Smiffo]

You don't need a diagram for 3 batteries - the leisure 2 are connected in parallel is the only difference.
With the Webasto it was easier to have a dedicated battery alongside it and saved having to run cabling from the leisure in the front ( it is far better to have heaters running directly from the battery nearby rather than a long cable and/or joins which will all contribute to voltage drop as heaters need a good supply of voltage). Charging cable is short also being just the other side of the bulkhead. You will still have lights, running water, sounds even though you are cold due to having flattened the heater battery.

I see.
I'm aware I am hogging the thread now, so one last question.
Does that mean the Webasto will run on battery with the engine off?
( Mine won't, it would kill the battery in 10mins I expect. )

[Oldiebut goodie]

Do you mean that yours is running off the vehicle battery or alternator or ....how? Or is it from a leisure and the battery is dead?
The idea of the heaters is so that you don't have the engine running to get warm.