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I suspect those transistors, too. They're super tiny compared to the ones in the controller I used. The controller box says it's rated to 6 A. Presumably, that's 2 A per channel. Can you read the lettering on them? You might be able to find a datasheet that gives their actual limits if you can identify them.Did you use a fuse tap to tap the +12 V supply for the LED controller box? If so, what position in the fuse box did you use? And, where did you connect the ground for the controller's power supply?If you have access to an ammeter, you should check to see how much current the LED strands are drawing at full brightness. Just connect them straight to a +12 V and ground with the ammeter in series. Without a controller doing any modulating, that will drive all LED's at full power and give you a worst case scenario.Does your dome light still function properly with the LED's and controller box removed?Swapping in a new controller box is a good idea. If the new one operates fine the old one is probably damaged. Most likely, the new one will suffer the same fate. Good thing they're so cheap. If you find out the transistors are not robust enough, it should be possible to replace them with bigger transistors, though you'd need to be pretty accurate with a soldering iron.
Thank you so much for the response! You were spot on on everything! So I did exactly what you described, and it operated exactly how it should for about 5 minutes, but then something weird happened. Now whenever I have the modified circuit board plugged in, both the dome light and the LED footwell lights stay on only when the car is running, no matter if I turn the controller off or on with the remote. When this is happening both the LEDs and Dome light are on at a diminished brightness. I've made sure that the trace was scraped off properly, and as I said it did work at first. Any ideas? I'm thinking I might have fried one or more of the transistors on the board, as now the all the colors are out of wack when being controlled with the remote(red won't work at all when selected, when I hit the green button on the remote the LEDs turn amber, when fading out, instead of turning off the color will stay lit as a dim teal and the dome light shines dimly). I have another unmodified controller that works great(albeit without the dome light control/fade). Just ordered 2 more controllers from AliExpress for about $2 each, so I'll be able to try it again when I get those in. Might need to get a more resilient controller like yours eventually. By the way, if it's too much work responding, don't sweat it, your instructable and help has been amazing as is. Seriously all the help so far has been more than enough.
Hello,Your controller is very similar. It's definitely pulse-width-modulated. I've annotated the picture you supplied of the circuit board. The black wire is not ground. It is the +12V line that feeds the LED strips (probably, I'm guessing a bit here since I don't have the board in hand and can't test it). At the bottom of the board, you'll see the transistors that control the red, blue, and green channels. They're a little smaller than the MOSFET's in the controller I used, but the operation is the same. For each transistor there are two pins on the left (gate and source) and one on the right (drain).The lower pin on the left side of each is the source. Each transistor's source pin is connected to the same trace on the circuit board and if you follow it around the bottom edge of the board, then as it runs up the length of the right side, you'll see it connects directly to the ground pin of the power supply coming into the controller (again: probably). If you leave the transistors wired as-is, the LED's will come on whenever the controller has power (and you turn it on via your remote).That's not the operation you want - you want the LED's to come on whenever the door is opened. For that, you need the source pins for each transistor to connect to the ground wire of the dome light. Your situation is tricky because your chips are surface mount. Unless you have the hands of surgeon and the right tools, you have little chance of desoldering those source pins without destroying the transistors.But, don't despair. Your board design allows for a pretty simple solution. I would cut the bottom trace just to the right of the third transistor. Use an exacto knife or razor blade to scratch through the trace. You'll probably have to desolder those white wires (for the IR receiver) to move them out of the way while you're cutting. That will disconnect the source pins from the controller's ground. Then scrape the left side of the pad, the side connected to the transistors' source pins and solder a wire there. That wire will be connected to the dome light ground wire (cyan wire in fuse box). You probably don't want to connect it directly. Use some sort of terminal or connector so you can unplug it easily.I'm not sure what you want to do with your 3-position switch. If you want the LED's to mimic the dome light operation, install the diode in the dome light circuit as I did. It won't give you the "always off" function though. Once upon a time I had planned a way to add that but have now forgotten it. If that's the operation you're looking for, I'm sure I could figure it out again. If you're looking for the LED's to function on a new 3-position switch separate from the dome light's switch, you'll have to describe to in more detail the behavior you're looking for.You might want to wire it up to your car as I've suggested in a temporary, quick-and-dirty, sort of fashion and see how it functions. You might find that the IR remote control will provide you with the always-off function you're looking for. Then again, it might have its own surprises.
Dome Light Triggered LED Footwell Lighting for a 2010 Honda Fit
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