12V short curcuit?

[DavidA]

On a California 2008, I've managed to shut down the 12V circuit - if it's not a single fuse, given that everything is off - is there a relay that trips the lot?

Any wisdom much appreciated.

 

[DavidA]

In addition, lights, water pump, controller ... etc ... none of these are now operational when the engine is running as they would if it were merely the leisure batteries that were cut off. It sounds to me like fuses but all the individual fuses certainly haven't gone? Is there one fuse or relay that can cut the lot?

 

[Martin]

Have you checked the circuit breaker above the gas bottle in the rear cupboard, however i thought this was just for the 240v supply?

 

[DavidA]

Have you checked the circuit breaker above the gas bottle in the rear cupboard, however i thought this was just for the 240v supply?

No, this is as you say the 240V supply. I've definitely blown something by shorting out one of the batteries (which I was changing!) - very dumb I know but now trying to sort out the mess. Heading off tomorrow, timing couldn't have been worse!

 

[Martin]

David, does the fridge and roof work OK ?

 

[Stu]

I think if you've lost that many consumers you'll likely have blown one of the bigger fuses further back towards the battery.

We're you doing anything specific at the time it went?

 

[John]

David all the 12V systems you are talking about logically would be powered from the starter battery A located under the bonnet.

Have a look at the self study guide (VW Technical Manual) that you can download from the clubs download section).

On page 40 it shows the power from the generator and battery A being fed through a isolation relay R and then a fuse S.

I would guess that these are located near the battery and the fuse would be fairly large as it would need to be able to carry a large current.

Sorry I can not help further at this stage and suggest that you have a look on the T4 T5 forum which is a good source for technical information for the transporter.

Let us know how you get on and if I can find any further info I will post it.

John

 

[DavidA]

David, does the fridge and roof work OK ?

Nope. The control unit is dead even with the engine running (normally this would be operational without the 12V circuit supply when the engine runs) ... everything connected to the 12V circuit is dead - that's what leads me to think that a relay or global fuse would be to blame, unfortunately I don't know of such a thing in the cali's electrics??

 

[Stu]

If you look at the not very detailed SSP

http://vwcaliforniaclub.com/downloads/t5_tech.pdf

One fuse appears to supply everything you've mentioned from the underseat fuse panel so I think you need to step back to the next panel, either under the drinks holder or I there there is another one under the bonnet.

 

[John]

David have a look at this link which is useful as it shows the fuse locations for the T5.

http://www.vwwatercooled.org.au/forums/ ... 64343.html

John

 

[DavidA]

David have a look at this link which is useful as it shows the fuse locations for the T5.

http://www.vwwatercooled.org.au/forums/ ... 64343.html

John

Excellent, many thanks - the answer lies in there somewhere! It's at times like this I wish I actually knew something about anything!

 

[John]

David the main fuses are in Fuse Holder A

There are some very large fuses Fuses 1 2 and 3 look a good starting point

Disconnect the battery first thou

John

 

[Stu]

David do you have a multimeter?

 

[DavidA]

Don't have a multimeter with me at the moment. Have a long drive tomorrow, might need to have a fuse hunt rather than a lunch stop - would be nice to get where I'm going with some function in the van!

 

[John]

David I don't advise you drive too far with out fixing this.

It will be obvious if one of the large fuses is blown as the centre section of the fuse will be missing so try and locate Fuse box A and just visually check the fuses.

John

 

[Stu]

From what I can ascertain -

Fuse S65 is an 80A fuse that protects the 2nd Battery.

Fuse S339 is a 50A fuse that protects the Additional (3rd) Battery.

The camping equipment fuse panel (charging unit (S60 30A), electric roof (S67 30A), interior lights (S47 10A), cool box (S340 10A), water pump (S341 5A) & display unit (S63 5A)) is supplied via the 80A fuse S65 which appears to be located under the seat.

It may be quite a large fuse which sits on it's own attached to the relay carrier plate.

If you've blown this fuse then something hefty has happened. If it were me I would remove all of the consumer fuses I mentioned above before replacing the large S65 80A one. Then one at a time replace the others and by process of elimination you should find your problem.

 

[John]

Stu,

you are right I think I have been going down the wrong road as I can see now that the systems lost look like they are Cali only leisure systems that, as you say, are powered from the leisure batteries.

I dont think there will be any faults in the system themselves as David shorted out the failed fuse when he was charging one of the battery's.

I may have read some where that the leasure battery's have a fuse on the positive connection, :?:

David can you give us some more information on which battery you were charging and which systems have been lost. :?:

John

 

[Stu]

Ahh yes, I missed part about changing the battery.

I've definitely blown something by shorting out one of the batteries (which I was changing!)

Both leisure batteries are connected in series so disconnecting one would still leave power on some of the system.

 

[Martin]

Is the big 80A fuse not for the heating system?

 

[Stu]

I can see SC29 which is a 25A fuse for the Aux Heater.

80A would seem a lot of power for the Aux Heater.

 

[Martin]

As you have mentioned Stu, I think we need to ask Alex to do us a print out of what fuse does what as the information is different in my supplement compared to the one in the downloads section. Mine says the 80A and the 25A are for the aux heater :crazy

 

[Stu]

I don't know if it does differ but I am looking at pre facelift and obviously yours is facelift.

I wonder what the heater uses 80A for, unless it's maybe some sort of igniter. The 25A is for the Control Unit.

 

[Graham]

Ahh yes, I missed part about changing the battery.

I've definitely blown something by shorting out one of the batteries (which I was changing!)

Both leisure batteries are connected in series so disconnecting one would still leave power on some of the system.

Huh? if the batteries were connected in series, surely the result would be a 24V system.

 

[Stu]

Graham,

You are indeed correct they are in Paralell. I'm not sure what made me think they were in Series. :doh

 

[DavidA]

Quick update - by shorting the battery under the seat while trying to disconnect and change it, the fuse that blew was a 50 amp fuse attached to the positive terminal of the second battery in the rear!

Problem solved - thanks for all the replies and information.