Retrofitting factory Trailhunter / Pro Grill and Light Bar onto lower trims

[Dead Horse]

This is probably not going to end well, but here we go. Maybe a smarter person can help me out. With wiring I am, at best, an amateur.

I have a 2025 TRD Off-Road Premium Hybrid, and I want the heritage grill because reasons. The heritage grill has a spot for a light bar, as those models come with it. So I thought that the 200-300 dollar factory light bar off of eBay would be a good route to take, surely getting 12v to an LED won't be difficult. Right?

Spoiler/TLDR - I haven't gotten it to work and I don't have a lot of faith that I will LOL

Part numbers:
Upper Trailhunter Grill (Bronze letters) 53101-35160
Lower Grill 53113-35030 or 35040 (both show on the back of the grill)
Wiring harness connector: 90980-12446
Light bar: 8121A-YY030

The factory light bar requires the high beams to be on for it to fire. This complicates the wiring, and I knew that going in. I just didn't realize how complicated it is. There are 10 pins on the back of the bar (and 12 wires on the inside of the bar from that connection LOL). I thought that I could find a few pins and make my own 12v connection and just utilize the factory Aux switches I have optioned on my 4Runner. NOPE.

I have the factory service manual (does not have wiring diagrams) and access to AllData (has pretty good diagrams).

Here's the connection point on the bar and the wiring pinout/diagram for the female connector.

Here's where it connects to the factory switch:

Here is the inside of that connection, note that there are 12 wires, not 10 to match the pins because WHY THE HELL WOULD WE MAKE IT THAT EASY?

Four of the lights pop right out when unscrewed. Three remain inside the bar and require further disassembly that I couldn't do in order to access.

On the factory connection, pins 7, 8 and 9 are ground. Past that? I don't know what's expected over those connections. 12V to any combo I tried based on that diagram resulted in bupkis. That's when I started taking it apart. The Tundra guys had the same kind of issue (starting a few years ago) and from what I can find...They gave up, drilled a hole in the back of the light and fished out the 12v and grounds and ran with it. This seems a bit more involved. Tacoma forums have a few similar threads and I found no solutions there either, and they've also had a couple of years head start on us.

Putting 12v to the individual lights, once removed, fires them right up. Each light has two pins. Simple. And I'd 100% just splice into all of them and run my own harness out the back...Except that I can't get to three of them. The way this light is assembled, four LEDs come right out, but the other three require the shell to be split. Pretty sure they're bonded/sealed together. I couldn't get them to budge, broke three trim tools prying on them. So I can just trace the wires and tap into them upstream, right? If I could find them. There's probably 40' of wiring in there that I can't see. The circuit board is 6-8 inches long and has a second wiring harness in it, no idea what that's for.

Speaking of NOT A DANG CLUE...Two of those heat sinks aren't lights at all, but mystery electronical wizard magic stuff wired in because WHY NOT.

Anyway. I'm the guinea pig. Keep throwing time at this light bar that is by all measures inferior to pretty much all my alternatives, or set it on fire and throw it off a bridge?


Laugh with me. Laugh at me. Ask questions, give advice.

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[Van Solo]

Oh Boy!

 

[Joe Dirt]

Hey if that light bar has lights in it then there is a way you can open it! You might have to cut open the case with the Dremel. Do a full forensic on it and then rebuild. Good luck

 

[KG7BTU]

I’m seeing the “CAN-“ and “CAN+” pins… those are CAN connections into the LED bar itself?

I’m guessing it will not operate without the proper communication with the network, unfortunately.

 

[KG7BTU]

If I were you, my next step would be to get someone with a Trailhunter and hook up a scope to the vehicle side of the connector to see if the pins are signals or just high/low 12v.

I might be able to help with this, in a few months.

Good luck!

 

[Vincenzo]

I’m scratching my head as to why you opened it up.

 

[Vincenzo]

Have you tried sourcing the factory harness? #1 is most likely 12 volts. Based on my research, LBAC is low battery alert circuit. Guessing LBDG is low battery ground??? The rest of diagram is pretty clear on polarity. Looking at DiodeDynamics and even they don’t offer a plug and play option. The path you are on right now, I think there’s a possibility of throwing lights on the dash trying to integrate

 

[Dead Horse]

Hey if that light bar has lights in it then there is a way you can open it! You might have to cut open the case with the Dremel. Do a full forensic on it and then rebuild. Good luck

Dremel might come out for a post mortem if I ruin it, but otherwise...I'm pretty sure I'd have to stick it in the over and heat it up to get the two (or more) parts to separate. So it's going to have to stay together for now.

I’m seeing the “CAN-“ and “CAN+” pins… those are CAN connections into the LED bar itself?

I’m guessing it will not operate without the proper communication with the network, unfortunately.

Also my guess. But hey. Somebody had to try it.

Too bad for y'all that I'm not that bright LOL

If I were you, my next step would be to get someone with a Trailhunter and hook up a scope to the vehicle side of the connector to see if the pins are signals or just high/low 12v.

I might be able to help with this, in a few months.

Good luck!

Yeah, it will require somebody with a Trailhunter/Pro that's smarter than me with a scope to figure it out after they're willing to tear into their new truck to tinker with a working part. So I won't hold my breath

I’m scratching my head as to why you opened it up.

Because I can't make it work without opening it up. See your comment about throwing codes if I plug it into a harness that isn't expecting it.

If I can skip the CANBus side of the house and just get 12v to the lights themselves, 1-This will be a cheap-ish way of getting a light bar into that grill and 2-I'll have positive control over the bar so I can light it independently of the high beams.

I'm sure I could track down the actual harness that connects it up on the passenger side into the vehicle harness as well as back to the switch, I saw the part numbers, so I could order them...But then I'm far past what a really REALLY good aftermarket light bar would cost.

I'll take apart anything. I ain't skeert. Dumb? Maybe. Skeert. No.

 

[ScoMay]

I am interested in your bold attempt because I too would love to be able to operate my light bar independently from the bright headlights. I admire your courage in attacking the inner workings of the Pro/Trailhunter light bar.

Not sure how much this previous install thread (“Heretic light bar, Baja fog lights & Raptor aftermarket lights installed in TRD Pro grill”) will help you, but it is from the Tacoma forum and was posted to our 4Runner forum by our administrator.

If you ultimately have to bail from your attempt to rewire an OEM light bar and decide instead to go with an aftermarket light bar directly wired to an AUX switch, then you might find it interesting as the OP states why he went with a Heretic light bar instead of Baja or Diode. (Note: The information may be outdated by now as it is from September 2024.)

I don’t know much about automotive electrical systems and would consider myself LESS than an amateur so ignore it all if this is of no help!

Another thread that MAY be of interest:
“Lightbar options to go with TRD Pro lower grill swap???”

 

[Maximus4R]

The RAVE kits also require cutting to get flush. I have one that’s notched with the bracket and a new rough country light bar (replaced due to moisture intrusion in the original) that I am considering selling to go with diode dynamics. Their new kit is 20” so a much better fit than the older 18” style… but the price is killer. The sport starts at $499 with the pro coming in at $650. I wasn’t even considering it at that price point but my ditch lights are diode and I like having stuff match. My other hope was the OEM bar but that looks like a shirking possibility.

Really do appreciate all the work you’ve done on it @Dead Horse

 

[Fisher]

@Dead Horse . I have the same vehicle as yours with the "Upfitter" switches as I see you do. When installing a brake controller and popping off the switch panel I found that the blank switch panel for the light bar was wired and the wires disappeared into another wiring loom. I was wondering if you had your bumper off yet to see if there is a pigtail to plug into. Those wires must terminate somewhere.

 

[Dead Horse]

The RAVE kits also require cutting to get flush. I have one that’s notched with the bracket and a new rough country light bar (replaced due to moisture intrusion in the original) that I am considering selling to go with diode dynamics. Their new kit is 20” so a much better fit than the older 18” style… but the price is killer. The sport starts at $499 with the pro coming in at $650. I wasn’t even considering it at that price point but my ditch lights are diode and I like having stuff match. My other hope was the OEM bar but that looks like a shirking possibility.

Really do appreciate all the work you’ve done on it @Dead Horse

I'd really rather not have to cut on the grill to get a light to fit, that would bug me forever. I'd be more apt to bolt a non-functioning factory light bar into place and call it good.

I've never had a light bar, are there like...Nubs on the ends to go into mounts? I need to look at that. The bracket that this light mounts into has slots and some plastic pieces to clamp down on the ends of the factory bar that if modified with a cuttoff wheel might accept another bar. 3rd image up top shows it best.

Also another long shot, but hey. When all you have left is straws, you grasp at them!

@Dead Horse . I have the same vehicle as yours with the "Upfitter" switches as I see you do. When installing a brake controller and popping off the switch panel I found that the blank switch panel for the light bar was wired and the wires disappeared into another wiring loom. I was wondering if you had your bumper off yet to see if there is a pigtail to plug into. Those wires must terminate somewhere.

Interesting. I might pull mine off and look this weekend. The wiring for the back of the switch is upthread, so I could verify if those exact wires are present (would need people without the aux switches to see if they have them too, for knowledge base purposes)...And I have the location of where the light bar plugs in at the opposite end. I'll have to dig to find the harness though. I didn't save it like I thought I did LOL

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