I have an air compressor powered off of my battery and I am also running underbody, interior, and bed led lights on the same power and ground as the compressor. There is an inline fuse for the compressor wired close to the battery and I added the LEDs on later on after. I'm now having a problem with the lights because the power slowly reduces and dims the lights after a few minutes of them being on.

I have no idea why this could be happening but the wires goes from the battery to the inline fuse, then is spliced to provide power to the LED lights' switch, and then continues on to the switch for the compressor. I worked in an old house once and the miter saw would suck up all the power right before the breaker tripped and this seems to be the same problem. It's like the power is being run down but I just can't figure out a solution.

Does anyone have any clue what it could be or anything I could do to troubleshoot?

 

What kind of draw does your compressor have? You could be over drawing the power system of the truck. With the compressor on, hook up a volt meter to your battery and make sur the truck is still able to charge the battery faster than the compressor drains it. Also, if the fuse is larger than what the truck can put out, you'll never trip the fuse but you can still run down your battery.

 

Compressor voltage: 12v
Compressor draw: 16a
Inline fuse: 30a

The compressor has an auto-off switch so even if I don't run it for a few days and I'm driving my truck around (battery would have the full charge), the lights will still dim after a minute or so of being on. I did get a faulty switch from the company the first time I received it. This faulty switch wouldn't even allow enough power through to allow the lights to put off visible light. Maybe I'll try a brand new switch rated for 35a and just let the power just go right through them. Or even do a little digging to find out what the max draw is on the lights and grab an inline for the power to them so that I don't burn them up. (Yeah I have a tendency to do that a lot when I get fed up with them)

I'll keep ya posted. Thanks.

 

Unhook the compressor and see if things change.

If not, your wire is failing. I had this happen to my hot wire running from my battery to the rear of my bed. Don't know why, but about 3/4 from the battery to the left tail light, I got a sharp voltage drop with zero load. I'm in the process of removing and replacing the hot wire.

 

Are you running power for the compressor in series with the LEDs? You said you spliced the lights in, but do they have their own ground or did you run power through the lights and then on to the compressor switch? What gauge wire is run for everything? If you could sketch the wiring diagram, throw it up.

 

Running 12 gauge solid copper wire power from the battery and ground to the battery. The compressor switch is at the end of both the power and ground. The LEDs are spliced off the same 12 gauge wire but use a smaller wire to run the power and ground to them. Now that I'm thinking about it, they do go far to be running on such small wires. The 12 gauge power runs from the battery and goes under the dash, where it is spliced. I didn't add any wire for he LEDs (just hooked onto the 12 gauge under the dash) but I did splice off of the bigger wire. I don't think this is a problem because I used way bigger than I needed to deliver the power where it needed to go and if I'm using the manufacturer's wire (actually shortened a little bit), there should be no difference than if I hooked up directly to the battery.

I did have the compressor unhooked for about a month and the lights still went dim. I might try adding more power wires for each set of lights instead of having them all on one single set.

Any suggestions welcome and I'm willing to try whatever I need.

 

And I have no clue how to post a photo off of my iPhone into here but when I get on the computer I'll draw out exactly what I have.

 

Hook your LED leads up to the battery directly, or a known working power port.

 

Unfortunately that would require un-installing the entire set. That is what I'm looking to avoid. I will try using a 12v charger pack so that I don't have to start cutting wires to test them.

 

Unfortunately that would require un-installing the entire set. That is what I'm looking to avoid. I will try using a 12v charger pack so that I don't have to start cutting wires to test them.