LED Truck Bed Lights - Multiple Controls

Hello all. I'm installing some LED strips under the bed rail in my new pickup. I would like to be able to control the lights in the following ways: 1) Install a door pin switch on the tail gate. Open the gate, lights come on 2) Install a cut off switch in the bed in case I need to have the tail gate off or down and want to turn the lights off 3) Turn the lights on using the built in upfitter switches in the cab, regardless of the status of the pin switch/cut off switch. The upfitter switches supply 12V. I could accomplish 1 & 2 above with no problems. The addition of #3 (essentially a 2nd 12V source) is where I get lost, but I'm very good at following directions, so I hoping someone can explain how to design. Thanks.

If you want everything to switch through the ground wire for the LED's as you described in #1 and #2, you can use an SPDT relay for #3 to provide ground to the LED's. 85 and 30 to ground 87 to LED's negative 87a not used 86 to 12V+ from the switch(es) in the cab. https://www.the12volt.com/relays/page1.asp the12volt • Support the12volt.com