Connected fog light wires in series to power 20" LED bar
05-21-2015, 03:31 AM
#1
JK Freak
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I connected them in parallel not series like the title says. It was a typo. Series would double the volts and I don't want that. I had my 20" LED bar connected to the wires of one of my fog lights (I removed my fog lights) and it would flash on then stay off. I figured it didn't have the amps to run it. So I got the two sets of fog light wires and connected them in parallel. I checked the volts and their at 12v, I checked with my voltmeter. The Amps doubled, I think, I don't have a machine that checks that ( unless my voltmeter has some way to check that that I don't know about). Now the bar stays on. I think the light bar needs 8 amps to run. So my question to you electrical geniuses is, is this a safe way to run the Light bar? Will I cause any electrical issues on my Jeep?
Last edited by RubiKing; 05-21-2015 at 04:58 AM.
05-21-2015, 12:30 PM
#2
JK Newbie
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OK...so if you'd wired it in series it would NOT double the voltage; you have a single 12V system, you would blow the fuse because a positive would be connected directly to a ground...or in this case possibly fry a module controlling the lights.
There's nothing unsafe about how you did it, but it's not how I would do it. The amps pulled by the light bar don't change based on how many voltage sources you put into it, and 8A is probably only slightly higher than the 2 stock incandescent bulbs on one 12V circuit. HOWEVER: your fog circuits use PWM independently for each bulb and you should always see 12V at each lead since that is the voltage supplied. by plugging it into one side the computer sensing the current draw saw more current than it is expecting from one bulb and shut the circuit down. running both fog light circuits to it the amp draw is distributed evenly across the two circuits so neither circuit is seeing significantly more current draw than they are expecting.
So, this is not unsafe, but I probably would not run it this way for a long time, just in case the circuits running parallel to each other like that cause issues with the module running the lighting. What I would do is use one side to power a relay and have the relay provide a clean, fused, 12V to the light bar...if you want to have the light bar tied to your factory fog light switch.
There's nothing unsafe about how you did it, but it's not how I would do it. The amps pulled by the light bar don't change based on how many voltage sources you put into it, and 8A is probably only slightly higher than the 2 stock incandescent bulbs on one 12V circuit. HOWEVER: your fog circuits use PWM independently for each bulb and you should always see 12V at each lead since that is the voltage supplied. by plugging it into one side the computer sensing the current draw saw more current than it is expecting from one bulb and shut the circuit down. running both fog light circuits to it the amp draw is distributed evenly across the two circuits so neither circuit is seeing significantly more current draw than they are expecting.
So, this is not unsafe, but I probably would not run it this way for a long time, just in case the circuits running parallel to each other like that cause issues with the module running the lighting. What I would do is use one side to power a relay and have the relay provide a clean, fused, 12V to the light bar...if you want to have the light bar tied to your factory fog light switch.