LED headlamp issue

[Colin Morgan]

The LED indicators I have seem to need about 5 volts to work properly - or they just fizz rather than flash.  It can be worth looking at what voltage is actually being supplied to the LEDS under different operating conditions - with various lights on, battery only, or with the engine running - to see how well the wiring system is coping.  (In the old days, remember how the the side lights used to dim when the headlights were switched on?)