Activate Truck Bed Lights from Multiple Sources

I have a 2008 Ford F250. I will be installing truck bed lights. There will be a total of 8 LED pods which has en extremely low amperage draw (less than 1 amp total). I want to wire it a little more complex than a simple single switch to turn it on/off. I need some help wiring in order for them to operate the way I want. I want them to turn on in the following three circumstances: 1. By way of a pop-pin switch. The kind that you install so when the tailgate is closed the pin pushes in and turns off the lights. When you open the tailgate the pin pops open and the lights turn on. Click HERE to see product 2. By a dedicated on/off switch in the cab that I can turn the lights on and off at any time, even when the tailgate is closed. 3. Finally, by tapping into the line that triggers the lights to come on whenever my existing factory bed light comes on (The one above the rear windshield) My initial thought was to use one relay and connect all three triggers to the 86 terminal inserting a diode on each of the three lines as to not send a signal back to either of the other 2. I am pretty sure this will work, but not sure if the use of diodes is necessary. Also under this method, I am not quite sure how I can have the pop-pin act as a trigger, because the way that switch works is by breaking the circuit at the ground. Not the hot lead. (You install that by connecting the ground from the lights to the spade terminal on the switch. Then the body of the switch is mounted right onto the truck, thereby grounding itself.) Now being that these lights only draw about 80mAmps (0.8 amps), I was wondering if there is a way I can wire this to my satisfaction without using a relay. If someone could please steer me in the right direction or suggest the best way to do this I would appreciate it. Please let me know if I need to provide more specifics.

1. The "pop-pin" switch you linked to should go to ground when the pin is not pushed down. I'm not sure how you planned to mount it to make it break ground when the tailgate is open or were you referring to it breaking ground when the tailgate is closed? 2. The on/off switch can supply 12V+ or ground. Do you want this to override everything (bed light and "pop-pin" switch)? 3. What does the lead going to your existing bed light switch? Is it 12V+ or ground? the12volt • Support the12volt.com

First off, Thank you very much for responding. I have searched all over the internet and no one has seemed to do all three of these methods in conjunction with one another. So I stumbled across this site as the DC circuit know all. So really appreciate the help. To answer your questions: 1. Correct. I think we are saying the same thing. Perhaps my terminology was wrong. When the pin is out (tailgate open), contact is made, and the circuit is closed, thereby completing the circuit and the lights go on. When the pin is pushed in (tailgate closed), the circuit is open (broken)thereby turning off the lights. But this opening/closing of the circuit takes place on the ground side of the circuit. Not the hot side. The way the switch is designed it doesn't appear that I can use it to break the circuit on the hot side. 2. I never thought of using the on/off switch to break the ground side. I see where you are getting with that. As far as override everything. I'm not sure I would call it an override, so much as to work independent of the two. Said another way, if I am rolling down the highway with tailgate up, all lights are off. I want to activate a new switch in the cab to turn on the new bed lights. 3. 12V+ for sure.

You're welcome. 1. I think we're on the same page. Use the switch to supply ground when the tailgate is open. 2. I would wire the switch in the cab to supply ground. 3. I would use an SPDT relay to provide a ground when the bed lights are on. Wire it as shown below connecting the switch 12V+ lead of the bed lights to terminal 86. Now connect all the negative outputs (from on/off switch, pin switch, and relay) to the negative lead of the lights and connect the positive lead of the lights to a constant 12V+ fused source. Diodes aren't necessary, but if you do use them, I would use 2 amp diodes to be on the safe side. the12volt • Support the12volt.com

This is great. Let me digest this all. Then I am going to draw up a nice diagram how it will look on my truck and link it here for your final approval. That will probably be tomorrow as I will not be on a computer for the rest of the evening.

I look forward to seeing it. You can use this button to add the diagram to your post. the12volt • Support the12volt.com

This is what I came up with. A few notes about my crude drawing: 1. The location of the wire runs are for clarity only. Everything will be run along the driver side frame. 2. Relay will most likely be tucked away in the Driver side A-Pillar as I can gain access to tap into the existing hot wire coming from that Factory light in there. 3. In reality there will be a total of 8 LED pods in the bed. 4 on the right and 4 on the left. I omitted the 4 on the left for clarity. I am well aware how to connect both strands together. Assuming this diagram is correct I do have 2 questions. 1. The style switch I plan to use in the cab has red and green indicator lights to tell whether it is on or off. (see attachment) I am pretty sure those will not work in this configuration. Am I wrong? Is there a way around that? 2. You mentioned to use an SPDT relay. I typically use a basic 4 prong relay with a 30, 85, 86, and 87 terminal. Can I just use that and attach a jumper wire connecting the 30 and 85 terminal to create what you posted above?

The diagram is fine, but I would mount the relay under the dash instead of behind the A-Pillar, resulting in less wires to run up into the A-Pillar and easier access if need be in the future. As far as the switch with the LEDs, I would have to see the wiring to accurately answer your question, but I would think it would be possible, however I would be concerned about it always being illuminated with the vehicle not running. Yes, an SPST relay will work. I just keep SPDT relays in stock as most shops do for simplicity. No need to stock both. the12volt • Support the12volt.com

Without seeing the wiring for the switch, I'll assume one lead of it is ground and it relies on 12V+ being switched to illuminate the green LED when in the ON position. If this is the case, you can use it to switch 12V+ to the relay and use two diodes to isolate the dash switch and the switched lead from the bed lights. the12volt • Support the12volt.com

My switch will be similar to the one in this article: Wiring an illuminated toggle switch Note the sentence:   Note most switches will not illuminate if they are on the 'ground' side of the accessory. For a toggle switch like this that opens and closes the circuit between the #1 (PWR) terminal & the #2 (ACC) terminal my application would have me connect #1 to a ground, # 2 to my Negative pigtail. That would leave #3 unused. The switch would work in terms of turning on and off my bed lights. But the illuminated light on the switch would not. I think you mean this. Tell me if this is correct. If I have this right it will also solve your concern of having the little indicator light on all the time when truck is off.