01-10-2018, 03:34 PM
(30-09-2018, 06:28 AM)jansens Wrote:(29-09-2018, 04:11 PM)Ruairidh Dunford Wrote: Do make sure you have a working ignition light otherwise the unit won't work.
I learnt that one on my MGB with the alternator light. I replaced all the other warning lights with LEDs but the alternator light has to work in both directions and enough current needs to flow to excite the alternator coils when you first start the car up.
Simon
An LED will work as an ignition warning lamp as long as you put a resistor with a value that spoofs a conventional bulb in parallel with your LED -i.e. across both legs of the diode. The original bulb is usually about 2W, so a resistor of about 70 ohms will be good for a 12V system. There has still been enough current going through the LED to light it on the couple of cars I've installed LED ignition warning "lamps" on.