hi i have got a rear hatch door with heating elements in the glass any one know how they are wired in is it a simple + to one side and earth to the other and a switch to turn it on and off or do they require a relay
have you got any existing wiring for it at present or are you fitting it to a bus that has never had it? if wiring from new, then yes, you will need an earth and a 12V feed to the window. the 12V feed will either have to go through a suitably rated switch (such as the original) or use a relay if the aftermarket switch you have/buy is of a lower rating like the diagram HorTs posted the 12V feed will need a 2.5mm CSA cable
Vans are done by Wire from fuse 10 (16amp red one)to dash switch with built in warning light then wire to one side of element the other side of element to a good earth. All wire to be 2.5mm2 The switches come up on e-bay quite often or Fit any switch with a warning light and if its not rated at 16amp fit a relay as shown on the diagram You could get all fancy and buy one of these http://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/timers.php that switches it off after 10mins
thanks ever so muchly you have all been a great help now who wants to volunteer to come round and put it in ;D
