[RidingRoadsAndTrails]

Wire colors for switch are blue with gray and black with gray.

Thanks again for the pic and info. I've found that Ford is not staying consistent with wire color coding in their harnesses. I don't know if it is a model year thing or a "use whatever we got when we got it" thing. The connectors and pin locations have been consistent, however.

 

[Robert24b]

If you have the wires identified behind that cover, all you need is a momentary switch to turn the lights on/off. The system is looking for a short to ground as a signal.
I don't know what the ford part costs but I bought this multipack for around 10 bucks. Electrically functions the same.

 

[Bob in MD]

surlyBill... you need to drink your beer faster

I have a 2017 T350 and want to add switch at fuse but manual does not identify cargo light fuse. Any idea on correct fuse

Bob in Maryland

 

[Xprmntl]

I have a 2017 T350 and want to add switch at fuse but manual does not identify cargo light fuse. Any idea on correct fuse

Bob in Maryland

For 2019 and prior, Fuse 32 under the steering wheel.
For 2020, there may not be a fuse and it's controlled by the BCM, see Cannot find fuse for Interior Cargo lights in 2020 Transit

 

[438TransitBuild]

OK, thanks for the pic, that helps.

I have that plastic cover, but there is no switch or indent for a switch in it. Behind the cover, there are 2 connectors; one that goes to the brake light and the other, with 2 wires, goes nowhere. I could make the guess that the second connector is for the non-existant switch. I could jump the two wires and possibly get the switch behavior or, worst case, blow a fuse. I think I'm just going to remove the cargo lights as my dimmable puck lights are much nicer and behave much more predictably anyway.

View attachment 158574 View attachment 158575

@RidingRoadsAndTrails did you end up figuring this out to install a switch there?

 

[RidingRoadsAndTrails]

@RidingRoadsAndTrails did you end up figuring this out to install a switch there?

I did not try. I removed the all the factory lights from the cargo area and use my house lights.

 

[438TransitBuild]

I did not try. I removed the all the factory lights from the cargo area and use my house lights.

Hmm. Can’t decide what to do, and I want to install my ceiling so I’m going to have to deal with those cargo lights soon. I think I’d like to keep them as an option but accommodating them in the ceiling would be a pain, and I’m no electrician at all (zero experience) so this thread is rather intimidating to me!

 

[BigKuma]

Sorry for resurrecting this thread. I can't seem to reconcile the implementation everyone chose with the 2020 Transit Wiring Diagram I bought on eBay. On the diagram, it implies that White / Blue wire is +12V ? While everyone here says White / Blue is pulled to ground to turn the lights on. Look at the other side of the light ( coil symbol ) on this picture, it leads to ground symbol through BK (Black) wire. Can someone explain this please ?

 

[Xprmntl]

Sorry for resurrecting this thread. I can't seem to reconcile the implementation everyone chose with the 2020 Transit Wiring Diagram I bought on eBay. On the diagram, it implies that White / Blue wire is +12V ? While everyone here says White / Blue is pulled to ground to turn the lights on. Look at the other side of the light ( coil symbol ) on this picture, it leads to ground symbol through BK (Black) wire. Can someone explain this please ?

View attachment 168248

There are two different white/blue wires, see:

No, I don't believe so. The switch at the back doesn't have 12V. It's a momentary switch that grounds the white/blue wire when pushed, and lets it float (at somewhere around 3V) when not pushed. This is an input to the BCM, which looks for a transition of that signal (from 3V to GND and back to 3V) as a command from you to turn the other white/blue wire on (12V) or off (0V). You need to find the white/blue wire that is the 12V output of the BCM, and put an on/off switch on that. The easiest place to find it is right behind the driver seat, where there are only 2 choices of blue/white wire in the harness. Strip a small amount of insulation from one of the two, and measure the voltage with the lights on. If 12V, that's the one to cut & switch (always-off or on-via-BCM). If it's 3V or GND, check to other white/blue wire.

 

[BigKuma]

I found that the light feeding white/blue wire was thicker then the momentary switch white/blue wire.
Here is my picture of the switch installation. I was too lazy to go get heat shrink connectors, so went with regular connectors and black "liquid tape".


Here is a close up:

I didn't bother to discover where it splits off, just assumed somewhere in the middle of the driver side second row window. White is the "to lights" wire (going to the rear), red is "from the ECU timed" wire (going to the front), dark red thick is "Always on 12V".

Switch mounted into the wall panel:

I got it on eBay, there are various colors. I really wanted one that glows in the dark, and this was listed as LED lighted, but I think the way we are hooking it up (1 load, 2 power sources) is not how it's meant to be (2 loads, 1 power source). And both sides have to be used probably, I only connected to one column. But, it's super cheap (2 for $8), large, has a lot of color options, and a nice rubber grommet around it:

2PCS ON OFF ON Heavy Duty 6 pin DPDT Waterproof Boat Marine Toggle Rocker Switch | eBay

Specification: Product Name: 6PIN Rocker Switch Position: On-Off-On Rating Voltage: 16A 250VAC / 30A 125VAC Temperature -25+85°C Contact Resistance:≤ 20 MΩ Insulation Resistance:≥100MΩ Lifetime: 100000hours Number of Ports: 6 Pins Material:Plastic & Metal Size: 36 x 26 x 30mm/1.41*1.02*1.18...

www.ebay.com

See the diagram in the 11th image of the listing.
Another good thing about this switch is it uses standard blade (1/4" ?) connectors. Those are very common at auto parts stores. And you can disconnect them easily from the switch if you need to pull the panel off completely.

WHILE YOU ARE THERE, cutting wires, find a thick purple with brown stripe wire. Connected the rear going part to your "Always On 12V". Insulate and don't use the side going to the front. Now you have the 12V socket in the very back of the van (is that a rare option ? I picked almost all of the options) always on.

PS: I am still a little concerned that the first 2 pages of this thread talk about GROUNDING the white/blue wire, while the last two pages discuss wiring it to 12V. Is that a year difference ?

 

[Xprmntl]

WHILE YOU ARE THERE, cutting wires, find a thick purple with brown stripe wire. Connected the rear going part to your "Always On 12V". Insulate and don't use the side going to the front. Now you have the 12V socket in the very back of the van (is that a rare option ? I picked almost all of the options) always on.

I don't believe an untimed, "always on 12V" was available prior to recent versions (2020+?). I have a rear 12V socket and it's timed, like the lights, to go off after 20 min.

PS: I am still a little concerned that the first 2 pages of this thread talk about GROUNDING the white/blue wire, while the last two pages discuss wiring it to 12V. Is that a year difference ?

Like you found out, there are two white/blue wires, the smaller gauge wire is the 3V "always on" that when momentarily grounded, is sensed by the BCM, which subsequently switches on the larger diameter white/blue, 12V wire for 20 min. I don't believe the Transit comes wired any other way throughout the years produced. The last two pages also, in part, give clarification on a suggestion by @HarleyHauler where he describes just wiring an on/off, SPST switch on the 12V side (which can be at the fuse) that turns the circuit off when one doesn't want the lights to function at all.

I got it on eBay, there are various colors. I really wanted one that glows in the dark, and this was listed as LED lighted, but I think the way we are hooking it up (1 load, 2 power sources) is not how it's meant to be (2 loads, 1 power source). And both sides have to be used probably, I only connected to one column. But, it's super cheap (2 for $8), large, has a lot of color options, and a nice rubber grommet around it:

2PCS ON OFF ON Heavy Duty 6 pin DPDT Waterproof Boat Marine Toggle Rocker Switch | eBay

Specification: Product Name: 6PIN Rocker Switch Position: On-Off-On Rating Voltage: 16A 250VAC / 30A 125VAC Temperature -25+85°C Contact Resistance:≤ 20 MΩ Insulation Resistance:≥100MΩ Lifetime: 100000hours Number of Ports: 6 Pins Material:Plastic & Metal Size: 36 x 26 x 30mm/1.41*1.02*1.18...

www.ebay.com

The switch you used is a 6 pin DPDT which will only provide power to the switch's internal lights when toggled to one of the two "on" positions, with active power to that side (the way you wired it, one side has power always, and the other side has power for 20 min when another switch in the system is grounded, like the door switches or the manual switch at the rear door). If you want the switch rockers to be lighted continuously, you'll need a 10 pin DPDT switch which has 4 more connections for its lights, and you'll also need to wire these to an ignition-switched 12V circuit, as not to drain your battery. Here are some helpful switch diagrams:

Wiring Diagrams

Learn how to wire a rocker switch with clear, easy-to-follow wiring diagram. Get step-by-step instructions for quick installation.

newwiremarine.com

 

[BigKuma]

I don't believe an untimed, "always on 12V" was available prior to recent versions (2020+?). I have a rear 12V socket and it's timed like the lights to go off after 20 min.

Sorry, I should have clarified that my "always on 12V" is from the Customer Connection Point by the driver seat. And that's what I swap with the "timed" wire feeding to the rear socket.

Like you found out, there are two white/blue wires, the smaller gauge wire is the 3V "always on" that when momentarily grounded, is sensed by the CANBUS system that subsequently switches on larger diameter white/blue, 12V wire for 20 min. I don't believe the Transit comes wired any other way throughout the years produced. The last two pages describe just wiring an on/off switch on the 12V side (which can be at the fuse) that turns the circuit off when one doesn't want the lights to function at all.

Ok, you are right, I was misreading it, there are a lot of "always on" and "ground" mixed together. I understand now, they disconnect thicker white/blue circuit from the lights to disabled the lights completely.

 

[Xprmntl]

Ok, you are right, I was misreading it, there are a lot of "always on" and "ground" mixed together. I understand now, they ground white/blue to disabled the lights completely.

That's not what I was saying. If one grounds the small, white/blue wire permanently, then there will be a short in the BCM, 3V sense circuit. This 3V circuit is only meant to be grounded momentarily, using a momentary switch. On the large, white/blue, 12V wire (timed on), some people use a simple SPST switch to control when the stock light circuit is able to be powered. In this configuration, the light circuit is either off or functions as stock, so nothing is being toggled to ground in this implementation.

 

[Moraflex]

I just realized that my brand new (2 days of ownership) 2023 has the same cargo light problem. So annoying having those 3500K LED's blasting my eyes out every time I open any door, then taking 10 minutes form them to go out. This switch is a great idea.

 

[Moraflex]

Update: Back by the rear door on the left side is the switch which turns off the cargo lights and keeps them off while the doors are open. Yaahoo no need to rig a switch.....More update: This switch does not permanently turn off the cargo lights. Once the van is closed up then re opened they come back on. It's a remedy but not a cure.

 

[Xprmntl]

Update: Back by the rear door on the left side is the switch which turns off the cargo lights and keeps them off while the doors are open. Yaahoo no need to rig a switch.....More update: This switch does not permanently turn off the cargo lights. Once the van is closed up then re opened they come back on. It's a remedy but not a cure.

Yes, this is a momentary switch that resets itself. Permanent solution is discussed, above.

 

[BradVol]

Update: Back by the rear door on the left side is the switch which turns off the cargo lights and keeps them off while the doors are open. Yaahoo no need to rig a switch.....More update: This switch does not permanently turn off the cargo lights. Once the van is closed up then re opened they come back on. It's a remedy but not a cure.

Look into using Forscan to enable the setting on the dash to have all the lights not turn on when a door is opened or the van in unlocked. It's called Police Dark Mode and there's two settings you have to turn on and there's another setting in the Body Module that doesn't do anything.

 

[Unlimitek]

Nope. I depress the button and the lights come on. Depress again and they turn off. Wash, rinse, repeat. Works EXACTLY like factory cargo light button in the rear but it's located at the slider door.
NOW, I will say, I only have the allotted 30 minutes before it needs to be reset but I can live w that. [emoji4]

Sent from my SM-N950U using Tapatalk

You claim that the factory cargo light button can turn the cargo lights on and off when pressed repeatedly. I have a 2018 Transit cargo van and that switch only turns the lights off and when pressed again, does nothing. To get the lights back on, I have to close and reopen one of the cargo doors. Are you sure the factory feature can turn the lights back on when pressed again?

 

[Sprinter_Owner]

You claim that the factory cargo light button can turn the cargo lights on and off when pressed repeatedly. I have a 2018 Transit cargo van and that switch only turns the lights off and when pressed again, does nothing. To get the lights back on, I have to close and reopen one of the cargo doors. Are you sure the factory feature can turn the lights back on when pressed again?

Why close the door, you can just press the button, and get 30 more minutes of light. I doubt they will stay on, if you repeatedly press the button, unless that is an Easter egg.

 

[Unlimitek]

I think there's a misunderstanding. I meant when I press the switch, the lights go off when the doors are open (which is good if you don't need lights). But after I turn off the lights using the switch, if I press it again, the lights don't come on - nothing happens - which is something you might want to do. The only way to get the lights back on is to close the door and reopen. So I was wondering why does my switch ONLY turn the lights off and not back on?