I have bought some ultra LED`s for my dashboard (in blue). These come with resistor already installed and are suppoesed to be a straight replacement.
When connected to a 12v supply (car battery) they light up no problem, and even light up on a 9v supply, however when installed in the dash they do not work at all. I have tried just one with the existing bulbs in situe and all the old bulbs work but the LED doesn`t.
Where am I going wrong? Can anyone assist please