Galaxy 94hp led fan mod

[wrongway]

Hi all , new here . I have a 94hp in a big truck mounted on the dash , i have 2 strips of wood velcroed to the bottom on each side of the heat sink to make the radio sit level and allow good air flow underneath . In any case i had this idea to hook a red led to the fan and secure it under the radio so when the fan comes on the underside of the radio will glow red . This will allow me to know when the fan is running so i can keep my talking down while it cools , also if the light stays on for a long time it could warn me of fan failure , not to mention i think it would look cool .
I can't seem to find if the fan runs on 5 , 8 or 12 volts . Looking at the schematics it appears to be 8 vdc but i am not sure . It seems J4 and J8 are power connectors for the fans and my single fan is hooked to J8 , i will more than likely hook on here . I don't believe the led will cause an issue with the fan operation as it is set up to support 2 fans , plenty of power .
My questions here are , does anybody know the voltage of the fan ? and , what is the best way to drop the voltage to around 2.5-3 vdc for the led . I know a 150 ohm resistor works great for 5vdc , but not sure on the value for say 8 or 12 vdc .
Thanks all .
Don

 

[wrongway]

I have been digging around the net and found this cool little led resistor calculator and thought i would post it here in case anybody is interested.
LED Resistor Calculator
You just need to know the specs of the led you plan to use and your supply voltage . So i have one answer , now i just need to know the supply voltage . I have attached 2 wires to J8 and ran them down and out of the heat sink . I guess i will hook a multimeter to the wires and get to talking , when the fan comes on i will have my answer . After that a quick trip to radio shack and i'll be all set .

 

[wrongway]

I guess this project is a bust . The fan runs almost all the time once you start talking . It is a variable speed set up and the fan initially starts to spin around 5 volts , as the heat increases so does the voltage . The voltage climbs all the way to 12 volts . Then as the temperature drops so does the voltage , the fan runs until about 2.5 volts and then stops . The fan also stops during tx . I have no idea how to power a led off a variable power source , so the options are to find a place in the circuit where a steady voltage is switched on and off with the fan or switch to an incandescent lamp which would glow brighter as the voltage increased . Being as the fan started running after just a few transmissions i can see no benefit as the light would always be lit . I would be interested in knowing when the fan hit 12v top speed , if i could get a led to light at that time i would be happy . In any case at least i managed to see how the fan system operates as i found a post from a few years ago wondering how it works with no replies . If anybody has any ideas on how to have a light come on at 12 volts fee free to chime in , i am thinking maybe a voltage blocking diode with a threshold of 12 volts , but will need to do some searching . My other hobby is pinball machines and video games , i know just enough to make me dangerous .

 

[Eastside]

I have wanted to build a cooling box for radios.