Monsoon LEDs not working
Monsoon LEDs not working Hi all. i am trying to change the lights in my head unit to blue leds. i used an analog multimeter to determine the positive and negative sides on the circuit board and i used 820 ohm resistors for every light. but none of them will light up. i thought maybe i installed them backwards so i flipped a few to test the theory and still nothing. Im at a complete lose. 
Copy & Paste Moderator
Joined: Apr 2002
Posts: 9,764
Likes: 208
From: Eastern MA
820 ohm sounds loo high.
What is the rating of each LED?
Here is an LED Calculator to determine the resistor you need:
http://led.linear1.org/1led.wiz
I entered LED Specs of 3.2V 20ma with a 14V supply (car running voltage) and it recommended 560ohm
If I enter 30ma instead of 20ma, the recommended resistor rating drops to 390ohm.
What is the rating of each LED?
Here is an LED Calculator to determine the resistor you need:
http://led.linear1.org/1led.wiz
I entered LED Specs of 3.2V 20ma with a 14V supply (car running voltage) and it recommended 560ohm
If I enter 30ma instead of 20ma, the recommended resistor rating drops to 390ohm.
https://www.superbrightleds.com/more...-mcd/267/1194/
These are the LEDs I am using. I fiddled around with my volt meter with the lights on and connected some of the pins at the bottom of the circuit board and I got the display to light up
Idk if that's helpful
I got 390 ohms on the resister calculator. But when I was messing around connecting pins I got a few of the LEDs to light up
https://www.superbrightleds.com/cat/resistors/
These were the resistors I used
The resistor calculator said I need a 1 watt 390 ohms resistor. Would 1/4 watt work?
These are the LEDs I am using. I fiddled around with my volt meter with the lights on and connected some of the pins at the bottom of the circuit board and I got the display to light up
Idk if that's helpful
I got 390 ohms on the resister calculator. But when I was messing around connecting pins I got a few of the LEDs to light up
https://www.superbrightleds.com/cat/resistors/
These were the resistors I used
The resistor calculator said I need a 1 watt 390 ohms resistor. Would 1/4 watt work?
Last edited by WhiteBird00; Feb 22, 2016 at 07:05 AM. Reason: Merge consecutive posts
Copy & Paste Moderator
Joined: Apr 2002
Posts: 9,764
Likes: 208
From: Eastern MA
I don't know what fiddling you did to get the display to light up or get a few LEDs to light up with that high of a resistor, but be careful you don't short out or over-volt something.
Looking at those LEDs, they are 3.5V, 30ma rated. Using the car's supply voltage of 14+V, you should be using around 390ohm resistor. I little higher is OK because it will give some buffer (470 ohm will drop the current to a safer longer-life rating instead of peak rating but a little dimmer so go between 390 - 470 ohm), but the 820 ohm you have is way too high.
Looking at those LEDs, they are 3.5V, 30ma rated. Using the car's supply voltage of 14+V, you should be using around 390ohm resistor. I little higher is OK because it will give some buffer (470 ohm will drop the current to a safer longer-life rating instead of peak rating but a little dimmer so go between 390 - 470 ohm), but the 820 ohm you have is way too high.
