Converting to Diesel ! What will fit !

[niloc]

If you go to a local trailer/towbar dealer, you should be able to purchase a bulb failure bypass relay unit. Basically, it is a couple of relays that take a signal off the car lighting and use a different supply to power the trailer lights. The relays are small and therefore do not trip the bulb failure indicator. When you are at the trailer/towbar place, ask them for a wiring diagram for the relays, as often they do not come with any. Twice I have done this with much success.
The relays require a separate power source, and there is a convenient one available on the nearside of the boot underneath where the aerial is situated. If your car has an electric aerial fitted, then there is a constant 12V supply there that can be tapped into with a scotchlock. Failing that, there should be wiring already installed for an electric aerial that may either be powered, or just needs connecting at the dash end.
Hope this info is useful.