[CaptainMorgan]

Hello guys, popping back in from a long break with a little something to show you that I just whipped up.

I used to have key ring that I installed two red LEDs into to match my other interior lighting that was all converted to red LEDs as well. I gave that to Will a couple years ago at a meet and just never got around to making myself my new one.

I also got the idea that I wanted it to be the factory blue/green with the other indicator lights, and go red when the cabin lighting circuit is on. Here is the key ring built on the bench, that really is the same key ring in all the pictures.







When I get a slight break from work (not happening until at least Sunday) I'll pop it in with a relay to turn off the blue/green when the red turns on. The relay will be wired in the circuit for the blue green on the power pin going in and out on the pin that is live when the relay trigger is not on. This lets the power flow right through during normal operation of the blue/green. Then the red LEDs will be powered directly from the same circuit all the other cabin lights are on, but it will also be connected to the trigger on the relay that will cause it to break the circuit to the blue/green. I'm sure I could wire this a little differently but the 5 pin automotive relays are a five finger sale at the yards, so I just have them sitting around.

[MeanMugga]

Glad to see you still kicking around Dan!

I like this idea... should turn out great

[CaptainMorgan]

Oh yeah I was never gone for good. I also have a project you will really like but it isn't for the car. I finally broke my fiberglass cherry and on a tough project.

[luckkky13]

Looks great Dan. glad to hear from you....

[beeblebrox82]

very cool!

[D76G12]

[MeanMugga]

Nice! I need to get back into glassing. I have a project lined up for my friend's car. He wants a custom console and box.

[CaptainMorgan]

Alright well I quickly realized when I went out and looked at my key ring in the car that I wired this one backwards. I forgot that because I installed it aftermarket as a red LED ring initially the factory plug was tapped into the overhead lights that are red. No problem, a quick little switch and I'm good to go.

I then went out and installed the key ring in the car and fished my extra wire for the aqua LEDs over to the junction box. I only need one wire because I just shared the ground connection on the key ring for the red.

I'm going to go see how far I can get tonight, but I don't expect to wrap it all the way up. I have a few steps.
1. Solder a "trigger" lead off the connection to the red LED power wire that will go to the trigger on the relay.
2. Crimp female connector onto aqua LED power wire.
3. Splice into power and ground for dimmable cabin lighting.
4. Hook up and secure relay.

That should be it, but I do work early tomorrow.

As it stands now it's back to functioning as the red LED key ring (much better than bland stock), just waiting for the other part to be installed to make it fully operational.

[jradams350]

[CaptainMorgan]

Well it'll be a tad bit longer.

It's been a while since I wired with the lighting and I forgot about a couple little tricks in how Chrysler did things. It won't stop me, just isn't quite as simple as I had hoped. I'll keep everyone informed.

[CaptainMorgan]

I went ahead and ordered some new relays and a diode for it, so I'll fill you guys in on what I forgot about.

The overhead lighting circuit does not have a ground. It has a positive and negative, but both return to the junction box (or BCM, forget which plug it's on). I was treating it like it was just another ground.

To make my plan work is pretty simple. I redo the grounds so that the aqua LED ground is wired completely separately from the relay and splice the ground connection for the relay into the negative for the overhead lighting. This way I am completing my circuit correctly with the red lights on to energize the relay, and I'm not mixing it up with a regular ground connection.

That should be a pretty simple fix, and I'll have it wired and tested with an old relay tomorrow night.


Also, I have enough spare parts laying around to build another one of these as a kit for someone. I'm sure there will be some interest .

[joe_]

Most cars are "negative ground". That means a "negative wire" and a "ground wire" are two names for the same thing.

[D76G12]

Maybe in this case - but I suspect if you started grounding out sensor wires instead of returning them via their ground wire to the PCM that things would go sideways. I could be wrong, though.

[cdmccul]

I like the idea - but I'm not sure I follow the outward appearance rules - when will it be red, and when will it be green?

I think a fun variation on your project would be to trigger the relay based on what the last signal from the door lock module was - red when doors are locked, green when unlocked. ehhehehe

[CaptainMorgan]

I know enough about car electronics, I'm not new at this.

What I'm telling you is that this specific circuit isn't grounded like the rest. In the same IP harness essentially everything does have grounds that attach to the frame of the car under the dash by the driver's right foot. This does not, but instead returns to junction block/BCM. I'm pretty sure it handles dimming functions for those lights by manipulating resistance on the return leg, but that part I'm just guessing since the FSM really isn't that specific.

cdmccul - that would be a bit more challenging. You would need more than just a relay. Relays are energized when the coil has a voltage applied to it, and immediately switches off without that voltage. What you want could be done, but you would probably want to get a bread board and build a specialized circuit for the job.