Have you tried using the Ship Scripter? When I made my ship called the Starburner 2000 and used the ship scripter to make a script for it, it actually appeared on freelancer explorer for me.

Try that.

Also try activating the mods, THEN use Freelancer Explorer!!?

FL Explorer is basically just a system editor.To add ships to your mod you can use 1very large xml script file or manually edit the ini files.
A basic ship can have entries in 4-5 different ini files, a ship with custom weapons,engine,shield & power plant can have entries in about a dozen diff. ini files.You have to copy every entry for every ship into you mod's ini files,miss any and you'll CTD when you try to buy the ship,this is a dawnting task for any noob.

I've only been moding for less than a month myself & I'm not looking forward to hours searching through ini files,copy & pasting entry after entry,but unfortunatly I haven't found another way around this myself yet

Your best bet would be to read the tutorials that are in these forums,that way you at least now what your looking for.

You will also need the permission of the origional creators of the mods & ships if you go multiplayer or offer it for download.

Well, here's my two cents...

1. Go download the H-Fuel Tanker mod I just put up for download here. When you remove the modifications to Constants.ini and Solararch.ini (both XML files are clearly labeled)... what you have left is everything you need to add a custom ship to FL.

2. Study each of the files I've included. Basically, here's what each one does:

HFuel_Tanker.xml appends an entry for a ship, creates an Engine and Powerplant that are unique to that ship, and then makes the appropriate entries to Good.ini, allowing you to buy that ship... and finally, at the end, puts the ship on sale at NY, NY., in place of the Starflier, and on Crete.

The Crete entry is a little special- it replaces one of FL's many "dead entries" in market_ships.ini- entries where a ship isn't really on sale, but there's an entry for it anyway (probably created by some sort've database that FL's game-designers were maintaining, and never cleaned up). At any rate... Crete normally only sells one ship- now it sells two- the Titan... and mine.

Hfuel_Loadouts.xml adds a Loadout that's appropriate to the ship to loadouts.ini... which is one of the steps needed to put the ship into Factions.

Hfuel_Encounters.xml adds a customized AI entry for the Hfuel Tanker, which not necessary... but is very useful!

Hfuel_Faction_Prop.xml adds the Hfuel Tanker to the Merchant Factions (i.e., everybody who flies things like Trains). It searches for a certain entry in faction_prop.ini, and if it finds it... it appends this ship to it. You could make this super-targeted... for example, you could just add this to the Liberty Police... or you can make it hit a bunch of places at once, like I have done here.

Hfuel_Npcships.xml is the final piece of the puzzle, and links the Loadout, the Faction_Prop and the Encounter together into a functional AI-piloted ship. In my case, I wanted it to show up all over the place (as a proof-of-concept), so I made it show up in Encounters from level 1-19. Again, you could adjust this however you wanted.

So... what do you need, besides a copy of my mod (minus the two xml files that I added for gameplay purposes)?

All you need... is a CMP/MAT/SUR in a folder... and a custom Icon, if you have one. So... if you wanna add new ships... all you've gotta do is change what I've made here, dump your CMP/MAT/SURs into a folder, and voila! With only a teensy bit of work (an hour or two at most), you could put a custom ship into your mod... and you can do this multiple times to make a multi-ship mod very, very easily