How can i test LED strip - Positive and Negative wire.

[Carl-BVI]

Just got puddle lights and just want to test and see how bright they are.

Whats a quick and easy way to just temporarily add power to test and see for a few seconds it works?

Any info is great

[Fitter]

they should be marked. wire with trace on it should be negative.

are they 12v or 5v, normally i use a 7.2v battery. hold one wire to a terminal and just flick the other across the other terminal. if its the right way around u will get a flash of light. if its not u get nothing and a little spark at the battery.

its not long enough of a connection to damaged the LEDs.

[Kal777]

LED's are diodes and will not accept voltage backwards. so if you put the negative wire on a positive battery terminal nothing will happen at all. LED's will only form a closed circuit with the voltage flowing through in the right direction.

best way to test them is with a 12v battery charger if you have one.

[Fitter]

12v battery charger onto a 5v LED will blow it.

hence why i suggested a LOWER voltage battery, its not enough to blow a 5V LED and is still enough to power a 12v LED

[Kal777]

also, a wire with a stripe does not always mean negative. in most cases it means positive but there is no real standard for it.

[Kal777]

12v battery charger onto a 5v LED will blow it. hence why i suggested a LOWER voltage battery, its not enough to blow a 5V LED and is still enough to power a 12v LED

this is true, but shouldnt the LED strip have a voltage rating? would have thought that most LED strips you would buy for automotive use would be set up with 12V LED's

[Fitter]

actually when it comes to speaker wiring, it does, its a universal standard, trace = neg, except on black wires where white trace = pos

Kenwood reverse it for some reason on their speakers and run trace on Pos wire, but for their headunits revert back to Trace = Neg wire.
EVERY other manufacturer runs the trace on the negative wire for both headunits and speakers.

this is my 1000th post

[Fitter]

would have thought that most LED strips you would buy for automotive use would be set up with 12V LEDs

Incorrect, automotive circuits run anything from 3v to 12v (when car off) and up to 14.8 when engine running, and therefore you can buy 5V LEDs for automotive usage

really good examples:

Ford Escape reverse light = 5v circuit.
doing a camera install where you tap into the rev wire for trigger doesnt work due to the lower voltage and it wont make the system turn on - need a Relay

2012 Holden Colorado tail lights = 3v but on the SAME wire runs 12v for the brake light

adding in a trailer plug.... requires 2 seperate wires for brake and tail... or lightbars on the top of the car

dual voltage wiring is whats happening in cars now.

[Kal777]

my understanding of car audio is that its colour coding is some what unique and doesnt transfer over to other electric applications. about 90% of all wiring ive seen uses the striped wire for positive, only exception to this is when using split core cable that uses red insulation and a black stripe for negative.

soo many people fail at wiring up car audio because it doesnt follow a set standard.

back to the LED's. if the rating is less than 12V then obviously a 12v power supply will not work.

[Fitter]

your understanding of car audio is out the window.

you work at repco, go an open a Headunit box and pull out the instructions for wiring it up.

pay attention to the speaker wires.

grey - front right
white - front left
purple - rear right
green - rear left

the wire with the black trace is Negative.

this is INTERNATIONAL standard for headunit wiring.

aftermarket speaker wiring, 2 sets of wiring provided with speakers- black trace = negative on both the grey and white wiring thats provided.
except Kenwood who provide 2 sets of wiring for their speakers, grey coloured for both, one set has a blue trace, the other a red trace - on the Positive wire.

as for it "crossing over" to other electrical applications - it does. that is called Canbus