# Problem with my Webasto Air top 3500



## IrishMike (May 1, 2005)

Hi,
I just went to use the heating system in the van and found it dead.
It is a webasto unit with a triple timer control.
The problem is there is nothing displayed on the control. 
No time or anything,
I checked all the fused I can find but cannot see anything wrong. 
Does anyone have any ideas?
Regards
Mike


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## richardjames (Feb 1, 2006)

It's either got a seperate fuse or the timer has died


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## IrishMike (May 1, 2005)

The Wiring diagram and Installation instructions say a seperated fuse holder is supplied but as yet I cannot find it. 
I will have to see if I can get the timer off the wall and see if it is behing it.


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## sallytrafic (Jan 17, 2006)

Webasto provide their looms premade with connectors fitted, as a result the inline fuses (there are 4 from memory) and bits and bobs like relays could be almost anywhere.


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## IrishMike (May 1, 2005)

Thanks guys,
I guess it is a pro job.
I had a look at the loom and it is shrink wrapped and sealed. there are a number of connectors and what look like could be fuses in the shrink wrapping but Other than splitting it there is no access.
It is a real bummer as it doesn't look much like the wiring diagram.

Now the question is take it to the webasto specialist or the van shop.
Decisions decisions.
M


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## sallytrafic (Jan 17, 2006)

Webasto unless yor van shop has fitted them


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## Chausson (Oct 17, 2006)

IrishMike said:


> Thanks guys,
> I guess it is a pro job.
> I had a look at the loom and it is shrink wrapped and sealed. there are a number of connectors and what look like could be fuses in the shrink wrapping but Other than splitting it there is no access.
> It is a real bummer as it doesn't look much like the wiring diagram.
> ...


Hi M
Try calling this number,they are in Stoke on Trent the guys name is Ian and is very good with these units, they are the main agents for webasto, good luck.
Company name= H Bowers tel 01782 599990

Ron


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## roadstar900 (Dec 1, 2008)

Hi Mike
I had the same problem try this
unscrew the control panel at the back of the the control panel you will see a type of plug unplug this for about 5 seconds and this should reboot your system.
hope this helps 
jim


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## IrishMike (May 1, 2005)

*Update*

Thanks for all the advice. 
I finally pulled my finger out and used brain to figure out what was wrong. 
In doing so I discovered a few things. 
I found a web site in the US that had all the manuals free for download for the Webasto systems. But even with these there was nothing covering my system. 
So back to basics. 
I started with the fuse boards in the van. I found there are three fuses connected with webasto systems on my Ducato. There is even one dedicated tot he timer unit. But unfortunately these were all fine. 
So then using a multimeter I checked to see if power was getting to the thermostat and the timer and it was. 
A quick look at the wiring diagram showed that the timer is basically a low voltage switch that enables the Thermostat to function. So I disconnected the timer and looped the cable to the thermostat. 
Bingo I had heat. 
So it is the timer. 
I disassembled the timer and found the cause. It looks like some condensation had built up in one corner of the timer. this corroded and shorted out a number of components. I cleaned up the board but unfortunately the corrosion had eaten into some the smaller tracks. 
As all the components are small surface mount ones I decided I would not try to rewire the board and replace the parts. (too fiddley). 
So off I go to buy a replacement timer I mean how expensive could it be? 
First I find that my model of timer was now obsolete but there was a replacement. I think mine had more functions and programmable days while the replacement has only three heat times that have to be individually enabled one at at time. 
The connectors and the mounting positions are the same and the new one looks a bit nicer. 
But the price including vat it was almost 84 Euros!!! 
For a simple switching timer talk about a captive customer base. 
OOH well we are now fully functioning and can plan the first outings of the year. 
Plopsaland to begin in April yippee. 
PS I also suspect this is one of the causes of the problems I had with the main cab battery. I think there was a constant small current being drawn by the corrosion , not enough to blow the fuse but enough to help hasten the end of the Battery.


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## Chausson (Oct 17, 2006)

*Re: Update*



IrishMike said:


> Thanks for all the advice.
> I finally pulled my finger out and used brain to figure out what was wrong.
> In doing so I discovered a few things.
> I found a web site in the US that had all the manuals free for download for the Webasto systems. But even with these there was nothing covering my system.
> ...


Hi
It would appear to me that you had the timer cheap, about 6 months ago I wanted an electronic timer for my airtop I was told it was a little over three hundred pounds, so please tell me where you purchased it from.
How do you find your airtop is it noisy from the fan and do you get a load pulsing sound from the pump please, our's is so loud we have to turn it off for some peace and quiet but then get to damn cold.

Ron


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