Yes, installing your own LEDs on your car, motorcycle or in your home is often said to be easy – but hey, if you need LED install help, it’s just as easy to ask.
Customizable LED strips can add a pretty awesome effect to anything. So, if you’re looking to add a LED strip and have it turn on with a dome light, there are several steps you need to go through first:
Determine if your dome light is positive or negatively switched
Which wire is disconnected when the light is off and vice versa
Establish the amperage draw of your LED strip
Calculate the proper fuse and diode to use
Once you’ve established these factors, there are two diagrams to use –
If your dome light is negatively switched:
If your dome light is positively switched:
Read common questions and answers on LED Bolts
Phil from Oznium
You’ve got the right idea. Please let me know if I can clarify anything below.
First, you need to figure out if the dome light is positively or negatively switched. This means, is the positive or negative wire always connected? Which wire is disconnected when the dome light is off? Which wire is connected when the dome light is on?
Most cars I’ve come across use a negatively switched setup. This would mean the negative/ground wire is connected and disconnected, and the positive wire is always connected.
Calculating the proper fuse
Once you’ve figured out the amperage draw of each LED strip from the technical info page, you can then calculate the appropriate fuse size. In your case, 6 x 9.5″ LED strips would draw just under 1 amp. The purpose of a fuse isn’t really to protect the LED strip, but rather protect your wiring in case of a short. In this case, you can use a 3 amp fuse and be just fine.
Calculating the proper diode
Diodes have an amperage rating, and you might as well get that is capable of handling anywhere from 2 to 5 amps.
The diode prevents current from running back into the dome light when you flip your on/off switch.
The diode is like a one-way valve. Current can flow from the dome light, but not back to it.
Check this out: https://www.the12volt.com/diodes/diodes.asp
Thank you for the explanation and diagram for switching led lights with some light connection, this is very helpful. I want to do the same on my vehicle but using a switch pod instead of a toggle switch. The dome light is negatively switched but when I provide power to the led light from my switch pod it is no longer turned off by the dome light. Seems as though it is somehow grounded from the switch even when using a schottky diode. Same even if I do not connect the negative wire from the switch pod at all. Any ideas?
Thank you for this! The explanation and especially the diagrams have been extremely helpful but I do have one question. When connecting my circuit to the dome light with the diode in line (negatively switched) , where do I connect the wire at the dome light? To the ground before the switch? Or after the switch?