Is This a Legit Trailer Light Fix for Tow Package?

Got some trailer light woes, and wondering if I am on the right track for a fix. I've got a 2001 TRD 4WD with the optional tow package installed when the truck was new, which included this black box 'converter' mounted behind the drivers side back seat that you can see in the pic below. The only trailer lights I get with the flat 4-pin connector to the trailer at the hitch is a right turn signal...nothing else works. All the wires from the flat 4-pin hitch connector end up here at converter box. In the second image below, I've peeled back the lining so that you can see where all the wires enter the box from below. There are four 5A fuses, and I've replaced them all. They are for R/L turn signals, running lights, and brakes to the trailer lighting. I've opened the box, and it just looks like a computer motherboard suspended in clear gel inside.

Dealer says this part is no longer available (of course!), and what little bit I have found online about this thing is that other folks have had trouble with them going out, but the latest info I could find about trying to replace it was from around 2009. I suspect this converted box has failed and why my trailer lights ain't working.

I'm thinking of just replacing the whole converter box + tow hitch harness with this kit instead, which looks to connect directly into the tail lights without having to do some iffy jerry rigging or splicing. Any reason I shouldn't go this route?

 

I always wondered what that little box was. mine is under the little fold down seat where the jack it. All my lights work except the trailer running lights. I will have to check the fuses.

 

If it is plug and play it can`t hurt to try it

I use 7 pin plugs hard wired in

It makes it great for testing lights and brakes on trailers I work on

 

i put in one of those plug in harness that go into the taillight harness. worked fine. i had to have lights when i moved to louisiana because i towed a trailer..hopefully moving back closer to home soon and will be towing again

although i think the kit i used was way cheaper than the one linked above i got it from autozone wanna say like 45$?? but its been a while since i bought it

 

yea pick one up from Amazon, i just installed on yesterday on my dads taco and other then some overly long wires it was all plug n play

 

Lights are simple, just going from a separate brake/turn light to a combo throws a twist into the works. you can fix the issue with a little soldering time and some diode. It save a couple bucks but a pre-made harness is easier. And soldering in tight spaces can be not a lot of fun.

Looking at that kit, for $5 in wire and diodes I might consider the solder route vs closer to $100 in convenience. iirc i bought a reese brand adapter for my 02 from wallyworld, much cheaper.