Max draw through trailer plug

[cgibs89]

Hey everyone. I'm finishing up the interior of my enclosed toy hauler and looking to do some LED lights (4, maybe 6, along the top corners) and a 2-speaker stereo (50W max, most likely) just for some tunes when fixing broken junk on trips.

My question is does anyone know the max draw we can pull from the trailer plug? The trailer is a tandem axle with e-brakes so it uses the 7-pin plug. I flipped through the owners manual and I can't find any specific fuse that could relate to the plug other than maybe fuse 72, "Auxiliary power point (rear)" which is 20A; Page 228: Fuse 72. I'm assuming it's probably 20 or 30 amps but I just want to make sure.

And to verify so I'm not losing my mind, the +12V is in the 1-o'clock position looking AT the truck receptacle, correct? Luckily the trailer already has two ceiling loading lights installed so I can tap from the existing wire but just in case I need to run new wire from outside the trailer. Going off this diagram:

 

[t_j]

Pin 4 is what you want.

It's controlled by the following in the the engine bay fuse box:

9 Trailer tow battery charger Relay
21 30A Trailer tow battery charge fuse (J Case fuse)


However its key on only so if you want to use it with the truck off, you will either need to bypass the relay for it or run a separate power line. Either way you should probably upgrade the truck battery to a deep cycle or add a second battery.