Which battery powers your roof?

[snowy55]

I've just checked with a volt meter and my electric roof is powered by the leisure batteries.
Tried the volt meter in the dash top, front of kitchen cabinet and the socket just inside the sliding door and all three show a drop in voltage while the roof is being raised/lowered.
The socket in the pullout ashtray showed no difference in voltage.
Due to other peoples sockets being wired up to different batteries I wonder if anything else was different.
Are other peoples the same ?

 

[briwy]

If that's the case I wonder if there is a cut off voltage (like the fridge/heater) when the roof wouldn't lower and you would have to use emergency lowering procedure.

 

[calikev]

It maybe why it tells you sometimes to start the engine to put a bit back into the leisure batteries to stop them dropping below the critical point

 

[Hotel California]

Still not convinced , i still tend to belive the roofhydrolics operates from the engine battery ( the oil pump it is) the controlunit might run on lesurebatts.
Who will give defintive answer...?

 

[Loz]

Just read the wiring diagram.. or find the fuse for the pump and see which fuse board it is on?
It would seem that the pump draws off the leisure battery from the volts drop noted above..

 

[Hotel California]

Just read the wiring diagram..

Done it , still not convinced....

 

[snowy55]

Still not convinced , i still tend to belive the roofhydrolics operates from the engine battery ( the oil pump it is) the controlunit might run on lesurebatts.
Who will give defintive answer...?

The above test was done with a volt meter what more proof do you need!

 

[Hotel California]

The above test was done with a volt meter what more proof do you need!

Don't know , there will be a drop using the controlpanel anyhow.
Did you mesure the engine battery at the same time?

 

[Pineweasel]

Take a look at the electrical system chart in the California self study document (in the Downloads section). It clearly shows that the roof hydraulic pump is connected to the leisure batteries.

 

[sidepod]

Fuse 17. 30A. Fuse holder F-SF.
Roof Hydraulic pump.
Powered from leisure battery, controlled by main control panel.

 

[snowy55]

Don't know , there will be a drop using the controlpanel anyhow.
Did you mesure the engine battery at the same time?

Just tried it at home with the volt meter connected directly to the starter battery. Turned on the ignition waited a few seconds for it to stabilise and no voltage drop at all during the operation of the roof.

 

[Loz]

It's quite clear from the wiring diagram that it's powered from the leisure battery.

 

[snowy55]

But my original question was are they all wired the same?
Some peoples lighter sockets are wired different to others.

 

[Hotel California]

But my original question was are they all wired the same?
Some peoples lighter sockets are wired different to others.

Now your talking ,
Do you belive everything the VW book says?
Have you compared fuse boxes with the book ?
Even dealers don't know the answers ...

Good you mesured the engine bat. , i do belive you ....but also wonder why some things are diffrent on the same verhicles.
I been staring at the wiring diagram for hours belive me.... , go it posterd above my bed.

 

[DM]

It maybe why it tells you sometimes to start the engine to put a bit back into the leisure batteries to stop them dropping below the critical point

Interestingly my T6 manual says to turn the ignition on but NOT to start the engine.

 

[sidepod]

 

[sidepod]

 

[sidepod]

 

[Loz]

Yup, that's how I read it.

 

[marshian70]

OK, question from an interested electrical numpty here. If it is the leisure batteries that power the roof, which kind of makes sense to me, why do you need to turn the ignition on before operating the roof?

 

[ArunAlec]

OK, question from an interested electrical numpty here. If it is the leisure batteries that power the roof, which kind of makes sense to me, why do you need to turn the ignition on before operating the roof?

It has been suggested that it's a safeguard to ensure that the roof is not operated by anyone other than the "key holder".

 

[bigmac77]

It has been suggested that it's a safeguard to ensure that the roof is not operated by anyone other than the "key holder".

I am sure this is the answer. My boys would love to try and squash each other in the roof bed but without the key they can't do it. And believe me they have tried.

 

[Loz]

OK, question from an interested electrical numpty here. If it is the leisure batteries that power the roof, which kind of makes sense to me, why do you need to turn the ignition on before operating the roof?

"Because vee told you to! "

 

[sidepod]

Does lowering the roof automatically open a front window ? This could be why the ignition needs to be on?

 

[Loz]

Does lowering the roof automatically open a front window ? This could be why the ignition needs to be on?

Now that would be clever... as long as the rain sensor says yes