You haven't given near enough information about what your working with. Why do you only want to limit to a SPST switch? most switches in most styles are available in other configurations. Why do you think your LED strip would need a relay? Does it draw more current than the filament bulbs used in the interior now?

All that said, it's possible that you would only wire the LEDs to the same fuse and circuit the interior lamps now use, running them in parallel to the existing circuit. But it's hard to tell with out being there to see what your doing.

First, Love your John Rodgers quote.

Much of what you say depends on the age of the vehicle. If the vehicle uses a CAN then there is an interior lamp relay which is usually run of the battery saver relay. If the courtesy lamps are on a CAN timer where they stay on for a pre-set amount of time after the ignition is turned off then the interior lamp relay is tied to the ignition.

Also, this is not something I understand but I do know of people that have had problems with mixing LED's and incandescent on the same circuits because of the different current requirements between the two bulbs. I believe a lot of these problems have been solved with the plug an play LED bulbs. Unfortunately when looking up the plug an play bulbs they're usually listed as vehicle, model and bulb location specific. There's not much on custom installations. I accept my ignorance about this may have me overstating potential problems.

 

Hello all,

I have a way I want my LEDs to work in my Toyota FJ cruiser and I need some advice on how to wire it to.

I want my LED strips in the footwells to turn on with switched power (ignition) when the doors open. So a relay signaled by the door circuit (or another solution). While also having a switch that I can toggle to turn the lights on when desired. I want to use a specific switch that is a SPST because I don't like funky looking switches. If anyone knows if this is possible with this switch then any help is appreciated.

“I want my LED strips … to turn on … when the doors open. … While also having a switch that I can toggle to turn the lights on when desired.”
In other words, you want the LED strips to turn on when either the doors open OR when you flip a switch. A simple diode OR gate will work.

 

You might find a solution here by running a second relay for the LED's so you can use your single door latch. There are also premade led harnesses available for light bars which come with the LED relay and circuit breaker. Harnesses with on\off switches are also available.

https://www.the12volt.com/relays/relaydiagrams.asp

https://www.amazon.com/led-relay-switch/s?k=led+relay+switch

 

What we need to know is your exact plan - what do you want to achieve in terms of features and level of automation.

Prerequisites:
- You have a hot wire (12V) available to power the LEDs. This can be the existing outlet for door lights, or any other supply if you need to.
- You have a trigger signal to indicate the doors are open. This can be the negative ground for existing door lights.

Level of automation:
- Do you want them to turn on, regardless of the manual switch position?
- Do you want a permanent-on and/or permanent-off position?
- Do you want the LEDs to turn on separately from the existing interior lights? If so, only if manual, or also when the doors open?

You need to clarify what you want to achieve. If you manually turn them off, do you want them to turn on again the next time you open the door?

I appreciate all the knowledge and help from everyone. I've put this project of mine on the back burner for a while and I'm determined to figure this situation out. So I've learned a bit more about how circuits and switches work since I've been back and know exactly what I desire now.

-I can get my hot wire by tapping into the dome light feed at the drivers junction box, I have the connector, pin, and everything remembered
-Ground, the door switches are ground activated just like a few members said in the thread earlier

Automation: I'd like the footwell LEDs to turn on with the open door circuit regardless of whether the switch is pressed/depressed/etc.
Then the LEDs turn on with the switch pressed but only with ignition power (so I'm not draining the battery)

I want a permanent off position

I only want the LEDs to turn on separately from the dome lights when I press the switch. Otherwise they should come on when the doors open. And yes If I turn the switch off I want the lights to come on the next time the doors are opened. Thanks for all the great questions. You've all been great help. I saw another member mentioned using a
diode or gate to accomplish my goal. I'm not sure where in the solution I would install those

 

“I want my LED strips … to turn on … when the doors open. … While also having a switch that I can toggle to turn the lights on when desired.”
In other words, you want the LED strips to turn on when either the doors open OR when you flip a switch. A simple diode OR gate will work.

You are correct about my goal for the lights and desired function. A diode restricts the flow of electricity to a certain direction so I would install those before the switch? So would I have the switch wired with ign power and always on ground and run the switch output to the leds? Then somehow tie in the open door circuit with the diode on the power side? Any help is appreciated.

 

lluminated Entry for Vehicles with Negative Door Triggers Relay Wiring Diagram

Here's the relay diagram from the 12volt website that 'back to school' recommended.