Link here to where someone has dismantled the basic controller:
https://www.zinreich.de/blog/inside-the-webasto-heater-rheostat/
It seems the pot/rheostat is 2.2kw - Googling a pot of that resistance seems to show that they’re expensive?
I’d like to have used this type from the series :
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F282567885676
But I think they are only 0-20 Ohms
Mine is the Airtop 200ST - so just before the CAN came in with the STC model I think.
I found the wiring ..
The white and red works for it to just be a cold blower I think.
It looks that red and black are the simple switch for on/off - with blue and white going through the rheostat.
It would be nice if I could wire a series rheostat in there to keep it looking the part in my 80” - but I would think the chance of the resistances matching must be almost zero...
What are the other wires that run to the rheostat controller for?
This looks quite neat: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F232190442696
I was going to go planar until a good 2nd hand Webasto came up.
When the Chinese copies the Yamaha PW50 - all their parts were interchangeable. Only the quality varied - so it’s possible ....
My Td5 does 30mpg.
I’ve been wondering what would be a good replacement engine come the day. The OM606 is smooth and they say good for a million miles - but that’s a fair job to fit and the 2nd hand motors are in smaller numbers and with bigger mileages.
Those guys at the paint shop are heroes - amazing that they give you space and let you sleep in their unit 😊. Seems like you’ve stumbled upon a rare kindness there 😊
In addition to the above - an early check is to look for dry pink residue from evaporated coolant - look around the ends of the hoses and in the drivers side engine mount, that sits under the fuel cooler.