Aux heater fan under car switching randomly and draining engine battery

[Lez99]

2008 California 2.5L Diesel. Seems like what is the aux fan for the cabin heater has been switching on randomly and when if unnoticed,. drains the engine battery. This is not the cabin fan, there is no air coming out of the pillar, rather some sort of a safety fan that seems to be running of the engine 12V battery. Is this even possible ?. It certainly isn't the engine bay fan. Last I've noticed it has come on, when I unlocked the doors and stayed on all night draining the engine battery almost completely. Sometimes, after starting the engine and driving for a bit, the fan stops and doesn't turn on again. Sometimes is just turns on randomly in the middle of the night. I'm not able to attach a video unfortunately

 

[Super Californilistic]

2008 California 2.5L Diesel. Seems like what is the aux fan for the cabin heater has been switching on randomly and when if unnoticed,. drains the engine battery. This is not the cabin fan, there is no air coming out of the pillar, rather some sort of a safety fan that seems to be running of the engine 12V battery. Is this even possible ?. It certainly isn't the engine bay fan. Last I've noticed it has come on, when I unlocked the doors and stayed on all night draining the engine battery almost completely. Sometimes, after starting the engine and driving for a bit, the fan stops and doesn't turn on again. Sometimes is just turns on randomly in the middle of the night. I'm not able to attach a video unfortunately

Hi Lez99,
Did you find a fix to your problem? I am getting the very same symptoms and the start battery gets emptied in 3-4 days. Any good tips are highly appreciated.

 

[Andja]

Hi Lez99
We’ve got a similar sounding problem with our T5.1 California and would love to hear if you resolved this issue and how. Fed up of paying garages for nothing as they can’t seem to solve it.
Tganks
Angrla

 

[Andja]

Hi Lez99,
Did you find a fix to your problem? I am getting the very same symptoms and the start battery gets emptied in 3-4 days. Any good tips are highly appreciated.

Any results yet? Desperate to find an answer as we are having same problem. Thank you. Angela

 

[sidepod]

Sounds more like the coolant pump than a fan?

Aux pump circulating hot water after the van is stopped.
Could be a failed temp sensor?

At the risk of stating the bleedin obvious, diagnostic scan?

10 minutes studying the fuse diagram should reveal a potential solve. Pull any fuses that may be involved, see if the drain.noise stops?

 

[BristolCali]

My first thought was a DPF fan but does a 2008 van have a DPF, I am not sure.

 

[cpjb@btinternet.com]

For me the problem of the random fan was solved by the uncoupling/disconnection of the the heater from somewhere under the van. The guy showed me when it was up on the ramps how he had to undo some plastic protector panel in order to get at it.

Since then I have resorted to electric fan for additional heat, but at least I'm not going to get a flat battery because of it.