Webasto Thermo top T help needed

[silverbullet]

Recently acquired a fleabay bargain but unfortunately the controller is missing, along with the fuel pump. It's a 12v petrol one, ex-Bluestar allegedly...I've got a wanted out but also trying to get a wiring diagram.
Any help or advice gratefully received

https://club8090.co.uk/forum/viewtopic.php?f=19&t=107682" onclick="window.open(this.href);return false;

[Oldiebut goodie]

I only have German manuals for this one - if they are any help.

[silverbullet]

Thanks, that's a pretty good start! It's DIN wiring with track numbers so I should be able to work it out.

Identifying the correct timer/controller (or the different variants) will be the next hurdle.

[Oldiebut goodie]

Any of the digital timers will work, like this oval one:


I've not worked on one of them but I have a feeling that they operate on just two switched heat settings - I may be wrong there though. They are 5Kw aren't they - a bit of overkill if it's going in a T3.

[silverbullet]

IIRC the factory fitted the BBW 46 which as the name suggests was 4.6kW. It is a water heater, so with 18-odd litres of coolant to raise I guess VW wanted a big'un. I want to integrate it with an auxiliary heater I have bought, so it can do double duty as a night heater as well as a pre-heater
I don't like the look of the oval ones tbh, they look too "modern" for me. The rectangular ones look identical but some are labelled "combination" and have a thermostat dial on the front, not sure how that affects their performance or application as they are meant for AirTop?

[Oldiebut goodie]

Yes, the combo ones with the dial aren't meant for coolant heaters as they don't normally have infinitely variable output settings. The thermo top t is sub-named BW50/DW50
You are looking for a 1531 timer then - part no. 905797 (12v) or possibly an older 1529 one - part no. 82774A (12v) but these don't seem to be very common.

[silverbullet]

Thanks for the part numbers and advice. I have found a UK stockist who have the non-variable 5-buttton type. Not cheap, but I've got a mate who will recon the unit for beer money and it cost me so little in the first place, there's some budget left to spend on making it a 100% safe installation. A reliable controller is a must-have in my book.