Bed Lighting LEDs - Can I tap into existing bed lights??

[Bbass5]

Question for the group:

I want to add in LED strip lights for extra bed lighting. Can I splice into the existing lights in the bed or do I have to splice into the wiring harness?

I got this awesome lighting kit from F-150 LEDs but the instructions say that I have to route wiring back to the cab and splice into the wiring harness in the rear passenger foot plate. I think it would be way cleaner and easier just to tie into the lights that are already there. I pulled the lights out to see if it’s possible and what the wiring looks like. Here’s the photos:

And here’s what the inside looks like for space determination:

What are your thoughts?

• Do you know if there are connector adaptors available to plug-and-play directly into the light?
• Do you know if I can use that green and black wire for the LEDs? I assume that would make the LEDs operate the same as the bed lights (when the tailgate opens, when you push the button, when you turn on the lights from the cab, etc.)
• Does anyone know where I can find a truck wiring diagram to verify that I can tap into this light?

Any guidance would be greatly appreciated. Thanks!!

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[Samson16]

What is the Wattage rating of your additional light strip? The circuit behaves as though all the bed lighting current flows through the push button switch. I would want to make sure the switch and wiring can handle the additional draw.
I like the thorough and well presented idea. Nicely put forward sir.
Following.

 

[FirstFord]

Great find! Based on the pictures on the company's website, they certainly appear to be superior over the factory Ford bed lights.

I thought I remembered something in the manual advising not to tap into the factory harness, and went searching for it. But it turns out that it does not appear to be applicable to you:

So you're in the clear???

 

[Bbass5]

What is the Wattage rating of your additional light strip? The circuit behaves as though all the bed lighting current flows through the push button switch. I would want to make sure the switch and wiring can handle the additional draw.

Good point, I hadn't considered that. The manufacturer say it was 6W for each strip, so 12W total (driver and passenger)

I guess I could always try and touch the wires to the unplugged light connecter and hope I don't blow something

I thought I remembered something in the manual advising not to tap into the factory harness, and went searching for it. But it turns out that it does not appear to be applicable to you:

So you're in the clear???

Well, since the kit I bought has instructions for connecting directly to the harness, I assume they've done their diligence on properly connecting.

 

[Buyer2021]

I got this awesome lighting kit from F-150 LEDs but the instructions say that I have to route wiring back to the cab and splice into the wiring harness in the rear passenger foot plate. I think it would be way cleaner and easier just to tie into the lights that are already there. I pulled the lights out to see if it’s possible and what the wiring looks like.

Per the product description on the page you link:

"You can integrate them with your OEM bed lights if so equipped or use our easy-to-follow instructions to tie them right into the truck's harness so they will automatically activate when your doors open, key unlock or via the dash control module."​

​

So, the instructions for tapping into the harness in the door sill will cause the LEDs to activate whenever a door is opened, etc.

Note that description invites alternate connection with the statement "You can integrate them with your OEM bed lights if so equipped" which would provide an alternate activation scheme.

Attached FYI are the two schematic cells for Bed Lamps (Lighting Package Level A); note this is from the 2022 Workshop Manual.

Note, too, that the Bed Lamp Switch appears to work by interrupting the GROUND (-)(the black/yellow wire in this schematic) to the lamps, not by interrupting the always hot power (+)(green/blue wire in this schematic) feed. LEDs being polarity sensitive, you'll have to ensure respect of that.

Hope that helps, Good Luck, Have Fun!

PS - I urge you to never use those damned strand-cutting taps in your vehicle - use PosiTaps instead, they never cut strands in a wire and make a super-secure connection.

 

[Bbass5]

Update 1 - I investigated my options during lunch. On the plus side, you can connect the lights to the plug and not fry anything lol

As a test, I plugged in the LED strip in place of the light and it works!

However, I’m glad I ran that test because I learned that you can only turn on those lights when you push the button. Opening the doors, or tailgate, locking/unlocking, nor approach were able to get those bed lights to come on.

So, while it might be easier to connect to those lights, it does not sync with the zone lighting.

Now I’m wondering if it would be easier to connect it somewhere under the back of the bed where the wiring harness comes in or run to the cab.

I found the Ford parts wiring diagram. https://parts.ford.com/shop/en/us/e...center-p-ml3z14a411d?pdp=y#/collapseRelated10
However, I may be making this harder than I need to…

 

[HammaMan]

Tapping into the tailgate's little LED light feed may be a better option. It comes on with exterior lighting. You can use diodes you can tap both of them so the strips come on both with exterior lighting and the switch itself. Same circuit illuminates high mounted LEDs and tailgate trailer LED

By diode protecting both when the rear stop lamp LEDS are on they will illuminate as well as retaining switch control.

There's a possibility to diode in front of the bed lights as well and tie their behavior into the same as described above thus giving the entire bed lighting similar behavior with the 1 caveat being that if the puddle lamps are on and you activate the switch it may trip the puddle fet until the next key cycle. That's the benefit of fets vs fuses, they reset.

 

[Buyer2021]

As a test, I plugged in the LED strip in place of the light and it works!

However, I’m glad I ran that test because I learned that you can only turn on those lights when you push the button. Opening the doors, or tailgate, locking/unlocking, nor approach were able to get those bed lights to come on.

So, while it might be easier to connect to those lights, it does not sync with the zone lighting.

Well of course, if you tap to the OE bed lamps your LEDs will only come on when you activate the bed lamps switch; the bed lamps don't come on with zone lighting!

If you want them to come on with zone lighting IMO your best bet is to make the connections at the door sill per the provided instructions.

Most likely if there were an 'easier' way to accomplish that, the folks at F-150 LEDs would have given instructions for that, don't ya think (an easier installation would make the product more attractive on the market, so they have incentive to find that if it's there)?

Yeah, you can make this a whole lot more complicated with yet other activation schemes / multi-point activation schemes. The fact that you didn't realize how the LEDs would work when connected to the bed lamps until you tried it suggests to me that, in your case, that would invite trouble. Good Luck!

 

[Bbass5]

Well of course, if you tap to the OE bed lamps your LEDs will only come on when you activate the bed lamps switch; the bed lamps don't come on with zone lighting!

yea..... I didn't realize that. I have a bed cover so I never see them.

 

[Buyer2021]

yea..... I didn't realize that. I have a bed cover so I never see them.

Then why the heck do you want them to come on with zone lighting?

Seems your perfect KISS solution would be to have them only come on with the bed lamps switch when you're working / needing light in the bed??

 

[Bbass5]

Then why the heck do you want them to come on with zone lighting?

Seems your perfect KISS solution would be to have them only come on with the bed lamps switch when you're working / needing light in the bed??

lol point well taken. I want the lights to come on when I open the tailgate. And the top light comes on when you open the tailgate. So I assumed that it would tie into zone lighting that way. Maybe I misspoke.

 

[mtnryder56]

Yes, I did this when I hooked up the morimoto licenseplate frame LED light. I wired it straight to the bed lights, and now I'm able to turn on the brighter backup light with the push of a button. LED lights take hardly any draw. Or at least not enough to have an effect here. Love it

 

[HammaMan]

yea..... I didn't realize that. I have a bed cover so I never see them.

Do you have the little illumination light in the tailgate? You may still be wired for it either way. It works with the chmsl LEDs. My post contains the connectors and pins in the diagram.

 

[mtnryder56]

 

[HammaMan]

Another point I found in forscan is that there's a trailer option in the puddle config indicating that there's a possibility that F250s may have an a puddle lamp circuit for trailers. Not sure how it works. Mine has 5 here but cargo lamps don't illuminate with puddle so dunno.

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