Ruby headlights.

[A7JoJo]

A couple of years ago after a difficult journey home from a Club meeting, I replaced the headlight bulbs in the Ruby for LEDs. They gave much improved visibility. 
Last night when operating the dip switch from main to dip,I lost both n/s and o/s lights and the ammeter read -25. Today I have tried a spare dip switch, put the old bulbs back in and checked all the wiring. The same thing happens, one of the functions from the switch gives no lights and the ammeter reads -25 again. It is obviously not the LEDs, switch or wiring?
Has any else had a similar experience or any ideas what is causing this?

[Ian McGowan]

You can't dismiss the wiring as a possible cause however much you believe that you have checked it; it is the only component in the circuit that you haven't replaced!
However I agree that it isn't the LEDs, or the dip switch so, there is obviously a short to earth of the wiring between the dip-switch (in the dip position) and the dipped beam filaments (or LEDs) of the headlights. POSSIBLY on one of the headlight bulb connectors inside the HL shell?

[A7JoJo]

Thanks Ian . Problem found, it was a short under the radiator mounting which was not easy to find. Thanks also to Classic Dynamo for additional advice.