I have two what I believe are Car Builder Solutions electric fan/heat demisters under the dash that are not working.

It would appear on initial investigation that the switch was wired to the coil side of the relay and vice versa. I also have no 12v going through the (wrong) side of the relay for the heaters themselves.

Now, this passed SVA as it is, so would have been working then and I haven't done any re-wiring since.

Switching the switch to the right pins on the relay is easy enough as is supplying a fused (15a?) feed to the coil side of the relay, but I need to know what the wiring of the demister units are first?

I have emailed CBS to see if they can help, but in the meantime has anyone used the same units?

I have a brown, blue and red wire to each of the two units.

I would guess, the two thick wires are the heater, and the other thin wire is the blower (using one end of the heater as earth).. Still might be wrong if there are all thick, the best way to tell will be a multimeter, unless someone else knows...

Dan