Under dash lights...

[MasterOfTheHat]

So I found some LED strips at AutoZone and I'm planning on mounting them under the dash for a nice soft glow at night. Getting them mounted and wired to a switch should be no problem, really, but I have to complicate things a little bit...

So I want to have the lights on their own switch, but I also want them to come on whenever the dash lights and/or the dome light are on. I've got to do some digging into the wiring diagrams, but I'm sure that the dome light and the dash lights all come back to the fuse box under the dash, right? Anyone have any ideas on how the circuit will look? Has anyone done something similar?

Ideally, I want to be able to:

1. Turn the lights on when the headlights/dash lights/dome light are off
2. Have the lights come on automatically when dash lights/dome light are on
3. Be able to turn the lights off independent of the dash lights/dome light

[Acidsniper]

Short answer, no you won't be able to do all 3 of those. You will however be able to do two of them.

1) Come on automatically when the dome light comes on or dash light, up to you
2) Switch to on/off whenever you want

Forgive the crudity of this, but here's roughly what it would look like.

Fuze panel hot side for dash / dome light ======\
Key'd on hot wire ======= <Switch> ========/ Both wires spliced together == >Light

So basically what you'd get out of this circuit is that you can flip the switch at any time (as long as the key is "on") and the lights will come on, other wise the lights will automatically come on whenever your dome / dash lights are on but the light can not be shut off as long as the dash / dome light is on. You'll basically have 2 wires spliced into the one "hot" wire on the light. One coming from the fuze panel hot wire controlling the dash / dome and one coming from your switch. As long as one of those is hot the lights will come on.

While this is possible, it's not really advised as if you leave the switch on, then turn the dome lights on it could overload the voltage to the wire for higher than what it's designed and could potentially be a fire hazard. I'm not an electrician by any means so there may very well be a much safer / better alternative than what I posted above.

[wjeffp2000]

You can do all three. You will need two switches. 1 st switch break the hot/headlights on wire through this switch. Second switch close a hot/key-on wire to the lights. You can also do it with a relay and a 3 position switch but that will get a little more complicated. You can also do it with a 3 position switch, you will just have to make sure the contacts are normally open and normally closed on the correct throw of the switch. Easy way is to use two switches.

[HOSS-06]

This can also be done with couple switches and diodes! if you are able to do some electrical work yourself you will need to make the wire harness with the diodes.
the diodes only let the power flow in one direction theirfore stopping the power from affecting the done lights and such..