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Bedlight when Tailgate opens mod

scott011422

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Hey guys

I was able to get my bedlights to turn on and off when I open the tailgate.

I did try to use the factory "TailGate Ajar" signal, however that ended up being a resistance based signal and couldn't get it to work.

I do have a fancier methode using timers and such, but due to complexity on getting power and properly sealing the electronics I decided to try the low tech approach first. The positive thing about the low tech approach is it will work for anyone that has bedlights.

The factory bedlight switch is momentary and uses two wires. One is ground (BK-YE) and the other goes to the BCM (WH-BU). To get the functionality I wanted I ended up using two switches. I purchased a nice stock looking hood\door pin switch and a gravity based ball bearing tilt switch for the tailgate. The plan is the door pin switch activates when the tailgate first opens, which is then broken by the tilt switch when the tailgate is about 1/4 open (Normally Closed). Giving me the momentary action the truck wants. The benefit to this method is when I close the tailgate, the bedlights are activated by the tilt switch at the 25% point, then canceled by the door pin switch. So times when my tailgate isn't open for the 10m run time window, the lights will turn off as I close the tailgate. (This is probably 90+% of the time for me) For those odd times the tailgate is open longer, I'll either forget and the lights will stay on for 10m, Turn the lights back on before I close the tailgate and let the tailgate turn them off, or turn them off with the factory button after I close it. This is fine for me.

On to the install:

I mounted the door pin switch on the drivers side of the tailgate right below the latch pin next to this little rib. The switch I chose uses two holes. One for the switch, and a threaded hole to hold it in. Once done there is no convenient access from this area to the bed light switch, so I just reached in and drilled a little hole to run the wire through. I found it much easier to pull the ProPower Panel as my bedlight switch harness was very short. I used 2 wire weathertight connectors for the main connection and also for the tilt switch. Not that it mattered, But I soldered the red wire for the connector to the (WH-BU) wire on the harness. The black wire got soldered to the door pin switch.

For the tilt switch, This got mounted in the tailgate to the bed step switch, just because it was in a good spot. This mounting angle you'll have to play with until you get the timing the way you want. I made a nice sheathed harness and ran this from the tailgate up to the bedlight switch. All set.

In this way the operation is as follows

Opening:
1) When the tailgate is closed the door pin switch is open and the tilt switch is closed.
2) When the tailgate first opens, the door in switch closes to ground, passing though the still closed tilt switch, activating the bedlight switch. Lights come on.
3) Once the tailgate reaches about 25% open, the tilt switch opens breaking the circuit.
4) Tailgate is fully open with the pin switch closed and the tilt switch open.

Closing
1) As the tailgate closes, the tilt switch closes when about 75% closed. Completing the circuit and activating the bed light switch.
2) When the tailgate fully closes, it contacts the door pin switch causing it to open and breaking the circuit.
3) Lights theater dim to off.

This tilt switch sucks. I purchased a Directed Electronics one. They make nice stuff. But its so small its very influenced by vibrations. Id say half the time it misfires when opening or closing. The little ball must be bouncing a little. I just purchased a pack of 5mm mercury switches and am going to make my own switch that will hopefully work a little better. Thinking of mounting a few of them all together in series hoping they wont all bounce at the same time. This would work with the Directed one, But its too expensive. 40 bucks for two of those or 5 for 10 of the others....

I'll update this post as I tweek things. Pics coming soon.


Ford F-150 Bedlight when Tailgate opens mod IMG_3414


Ford F-150 Bedlight when Tailgate opens mod IMG_3413




Ford F-150 Bedlight when Tailgate opens mod IMG_3415


Ford F-150 Bedlight when Tailgate opens mod IMG_3419
Ford F-150 Bedlight when Tailgate opens mod IMG_3407


Ford F-150 Bedlight when Tailgate opens mod IMG_3417



Ford F-150 Bedlight when Tailgate opens mod IMG_3420
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tilefordude

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did you add the auto close?
 

fordtruckman2003

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The lights come on. Hard to see when it opens but you can definitely see when it closes.
 

kb2755

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Yeah I assume this is about the bed lights. I’d love to have that, but without power tailgate likely won’t be possible.
 

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fordtruckman2003

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I've had thought in my head for how to do it but I'm curious what this person did to pull it off.
 
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scott011422

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No, all power tailgates can fully auto close
 

fordtruckman2003

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Hmm I was thinking that was not a momentary switch. Interesting.

Where does the 10 minutes come in?
Is that a built in timer from the BCM?
 

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scott011422

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Hmm I was thinking that was not a momentary switch. Interesting.

Where does the 10 minutes come in?
Is that a built in timer from the BCM?
Yep, All in the BCM. I'm assuming its the following, but im not sure

726-46-02 xx** xxxx xx-- Cargo_RampDn_Duration_Cfg (CRDDC) • Milliseconds = Hex2Dec(**) • Range: 0 - 7000

726-46-02 xxxx **xx xx-- Cargo_RampUp_Duration_Cfg (CRUDC) • Milliseconds = Hex2Dec(**) • Range: 0 - 7000
 

fordtruckman2003

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Could get by with a momentary pulse when opened and just let the lights shut off after 10 minutes if that is the built in shutoff. Couple LED lights don't draw much power.

Not sure the trigger for dropping tailgate but if that is also a momentary pulse then tap that. Diode isolate of course to prevent opening tailgate with lights.
 
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scott011422

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Could get by with a momentary pulse when opened and just let the lights shut off after 10 minutes if that is the built in shutoff. Couple LED lights don't draw much power.

Not sure the trigger for dropping tailgate but if that is also a momentary pulse then tap that. Diode isolate of course to prevent opening tailgate with lights.
That's the more complicated way I was going to start with. Prox switch, Relay, timer for pulsing, enclosure, powers and grounds, ect. Went simple first. This way is my backup, Defiantly more my cup of tea.
 

fordtruckman2003

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That's the more complicated way I was going to start with. Prox switch, Relay, timer for pulsing, enclosure, powers and grounds, ect. Went simple first. This way is my backup, Defiantly more my cup of tea.
Saw old post on f150forum they did exactly as I described connecting tailgate unlock wire to bed light wire with a diode and claimed it works fine. Not sure if 21+ use a ground pulse to tailgate like the 2018 on that thread.
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