Webasto issue - controller crashed - T46

[dennismo]

In need of some help… away camping at the moment and have a Webasto heater that seems to have some issues. It was fitted by @Absolut5 a few years back and has been pretty flawless.

I didn’t actually use it last night as we are on hookup so had a fan heater on before bed. This morning, I noticed the controller was lit up with a display I hadn’t seen before.


Pressing the buttons doesn’t seem to do anything at all. It’s definitely not “on” (Heater isn’t running). It just seems to have crashed…

Wondering if anyone knows how to “restart” it? I’ve tried pressing and holding buttons and when the power button is pressed for 10s it displays a T46 code, which the manual says is an excess current fault / “short circuit at switch output”…but the setup hasn’t changed at all, so I’m slightly confused as to what is causing it…

Any thoughts / help would be gratefully received!!

Thanks team

 

[Mud Digger]

have you tried powering down from your Battery it might of sent a spike to it hooking up to the mains as your battery charger powered up

 

[dennismo]

Thanks @Mud Digger - this is a helpful thought… I guess the only way to do this would be to take the front seat off to access the battery in order to “unplug” it?

 

[Mud Digger]

Thanks @Mud Digger - this is a helpful thought… I guess the only way to do this would be to take the front seat off to access the battery in order to “unplug” it?

do you not have a isolation switch from your battery or a fuse board for the heater circuit pulling the fuse would be easiest Absolute would of put an in line fuse to it for sure probably accessible if you have not got anything fitted

 

[Mud Digger]

do you not have a isolation switch from your battery or a fuse board for the heater circuit pulling the fuse would be easiest

unplug your hook up too might be high charger going into the battery

 

[oldiebut goodie]

Looks like you have something that is switched on by the switching output and it is shorting or drawing too much current. You will have to trace the black switching wire to see what it is operating. If it isn't connected to anything you can disconnect the pin from the plug ( insulate the pin afterwards) as it is only used for switching things like relays for vehicle fans etc.

Don't just guess at what is happening - the code tells you!

 

[Mud Digger]

@oldiebut goodie if he can get to the plug he could just unplug it.. and try a reset he is in on a campsite right now not guessing at it looking for a temporary quick fix

 

[oldiebut goodie]

Why try a reset when the code tells you the fault? I've indicated the temporary quick fix!

 

[Mud Digger]

Why try a reset when the code tells you the fault? I've indicated the temporary quick fix!

No worries i went just with the over currant, not the short circuit side we don't know if the guy even has a meter with him or any tools i did't interrogate the situation

as he has a heater if needed so he wont freeze ...

 

[Absolut5]

replied to your email earlier…

 

[dennismo]

Guys - thanks for all your replies - really helpful! To help others (if anyone else experiences the same) @Absolut5 (who fitted it) think it’s either a faulty panel, OR the connection between the heater and the panel under the front floor mat may have got damp and be corroded…
Thinking I might need to take it to someone when I’m back home in Sheffield…

 

[oldiebut goodie]

The plug for the controller is 32cm from the controller if you want to disconnect the black wire, should be easy enough access if the installer left enough slack for easy replacement/removal ( not all are foreseeing enough to do so ).

 

[dennismo]

Will see if Jason can remember where I need to look for this, and then can potentially have a go… though I may just wait until I’m back from this trip now… Thanks all - your help so appreciated!

 

[oldiebut goodie]

Take the controller off wherever it is mounted ( either clipped in a plastic mount or double sided sticky pads ) and you should be able to pull the cable gently to see if you have enough slack to access the plug through the hole under the controller.

 

[IestynD]

Looks like you have something that is switched on by the switching output and it is shorting or drawing too much current. You will have to trace the black switching wire to see what it is operating. If it isn't connected to anything you can disconnect the pin from the plug ( insulate the pin afterwards) as it is only used for switching things like relays for vehicle fans etc.View attachment 151793

Don't just guess at what is happening - the code tells you!

Hi all,

Sorry to dig up this thread. I have this exact same issue. What was the end fix please?

My Van recently had solar added to it!!

I am happy to trace the black wire but before I do I need to find it!! Is that plug into the heater (under my van) or into the control unit inside the van??

I assume there is a loom Connecting them both together and hope the black wire isn’t connected to anything. I do have a remote control for my heater so not sure if that makes any difference.

I need to sleep in my van tomorrow night and Saturday so really want to get the heater working!

Thanks for any input.

 

[IestynD]

Just re read the comments from oldie about that plug being 32cm away…. I can have a good look for that tomorrow.

My main question is if the wireless remote control will use that and if that could be causing the problem ?

Thank You.

 

[Johnnyconverter]

Hi, Long time reader first time poster - I too have an error on a new Webasto - Wired from a dedicated switch in the board with a 20a fuse, I got involved in this thread because the initial error was T46 but now I have removed the Remote control unit which seemed to resolve that issue, but now i have internittent fluttering of power Any help would be greatly appreciated -
John

I have uploaded a video of the flicker

 

[oldiebut goodie]

Poor connection or broken wire making intermittent contact. Either in the controller power wiring or the main ecu plug not pushed fully home. Check the controller fuse - either 1A or 5A.
What do you mean "dedicated switch in the board" the heater should be powered directly from the leisure battery?

 

[Absolut5]

The only time we have seen this issue with Webasto is the controller plug and socket getting corroded.. or at the heater end where a extension is added.. normally under the cab floor carpet/mat, as the gets damp from leaks or from wet shoes over a period of time

 

[Johnnyconverter]

Poor connection or broken wire making intermittent contact. Either in the controller power wiring or the main ecu plug not pushed fully home. Check the controller fuse - either 1A or 5A.
What do you mean "dedicated switch in the board" the heater should be powered directly from the leisure battery?

Thanks for the reply, I have rewired direct to the battery with an inline switch so I can isolate the heater checked all the connections - and they look solid - I’ve Noticed that the controller starts fine but as soon as the heater draws any power it switches off even the led on the switch goes dim - no fuses have blown and I’m stuck for ideas now