The webasto installation manual

Why not give the model of the heater or a link to the installation manual? So the guessing can stop

 

Why not give the model of the heater or a link to the installation manual? So the guessing can stop

This is the installation manual but it does not contain a detailed instruction on the blower connection. Just the picture I provided.

 

The manual changes a lot. I kind of had something different in mind!!

Pin 3 isn't a CAN pin. I can't say what it does, but I can say it's not. You would have to connect two wires for a CAN bus. They would be twisted together from one end of the harness to the other and also twisted all the way right up to the connector itself if there was one there... the pictures look like there isn't even a CAN present on the connector.

The schematic in the manual sheds a bit of light on things, but I'm still stumped and have to "tap out" at this point.

 

The manual changes a lot. I kind of had something different in mind!!

Pin 3 isn't a CAN pin. I can't say what it does, but I can say it's not. You would have to connect two wires for a CAN bus. They would be twisted together from one end of the harness to the other and also twisted all the way right up to the connector itself if there was one there... the pictures look like there isn't even a CAN present on the connector.

The schematic in the manual sheds a bit of light on things, but I'm still stumped and have to "tap out" at this point.

Okey, thanks for the help. I measured on the relay that there is no voltage drop between pin 30(vcc in) and pin 85(gnd) but there is a 12v drop between pin 30 and pin 87(voltage out). There is also no voltage drop between 85 and 87 nor between 85 and 86. How is this possible? How can there be no voltage drop between 30 and 85, and at the same time no drop between 85 and 87, while there is a 12v drop between 30 and 87?

 

The drop between 30 and 87 would be right as those are the pins that are switched.
As far as 86 and 85 being the same voltage either it is a switched ground configuration (fairly common in automotive stuff) and at the moment the relay should be off, or there is a bigger problem somewhere.

 

The drop between 30 and 87 would be right as those are the pins that are switched.
As far as 86 and 85 being the same voltage either it is a switched ground configuration (fairly common in automotive stuff) and at the moment the relay should be off, or there is a bigger problem somewhere.

Yes I know that the drop between 30 and 87 is right. What I can’t understand is how 85 can be both 12v and 0v, since there is no drop between 30-85 and 85-87. Could it be a bad ground connection?

 

Could be. Have you tried any Audi forums by any chance? While I was looking around for information I found several posts about Webasto heaters, but nothing like your question. You may have better luck there since they have actually done it before.

 

You gave a link to your heater, one that is a what we would call a *block heater* to help an engine start in cold weather or not freeze overnight. But you also showed pictures of someone wiring one to their cars heating system. Something your Manual doesn't show. The one in your manual has it's own dedicated controller and doesn't even show a way to wire it into the cars controls since it wasn't meant to work like that.

My thoughts, and just my thoughts, are that the one made to wire into the cars heater controls was more expensive than the block heater, and you are trying to make the block heater do what the more expensive one does. There is probably another circuit involved with the one that gets controlled by the cars heater controls. So I'm assuming that you won't be able to do what you want to do.