I think it's the seventh gym ( so you can get into Lake Acuity) Take part in the events there and then fly to Veilstone City and get into the Galactic Warehouse (its on its own right next to the big building) There is a Team Galactic Grunt here who runs off and leaves a key behind. Pick up the key and get into the Warehouse. Find your way through under the Warehouse into the main building and then find your way to the top of this building and fight Cyrus. He gives you the Master Ball when you beat him, and then head into the teleport that takes you to the prison cells that hold the 3 Legnedary Psychics. Release them, and then some Galactic Commander runs up behind you and takes the red chain thingy.
After that, go to the entrance to Mt. Coronet that is on the left side of Hearthome City. You need Rock Climb also. This can be found in the snow on Route 217 (where you can barely see on account of the blizzard) Find your way around to the side in here that has the spot where you can Rock Climb. Find your way around in this natural maze (sorry I can't be more help here but I forgot how to get there) till you find your way to Spear Pillar. I can tell you this, if you get to a point where there is one lone Galactic Grunt who doesn't fight you and is standing in front of a doorway, you've gone the wrong way, so go out and find your way further up from that location. Once at the top, save, and then enter the partner battle with your rival against the Galactic Commanders. After that, fight Cyrus again and then watch as he calls forth Dialga. Before you fight Dialga, the three Legendaries that you freed earlier come and limit his powers. Now, fight Dialga and try to catch him with an Ultra Ball. This is pretty easy as he is only at Lv. 47, and I caught mine with just 3. Congrats, you now have Dialga!
wow
In Pokemon Diamond, you get Dialga before the 8th gym battle. After you beat the 7th gym, you battle at the peak of Mt. Cornet, Spear Tower, and battle, preferably catch Dialga, then you can access Sunyshore City. In pearl you battle Palkia.
in diamond you get him at spear pillar after battling the seventh gym and went to veilstone city and defeated them there Pt after you finished the elite four go to spear pillar you cant get dialga on pearlin Pokemon lake you can get him in map 16 with mewtwo and areus
You can find the 2nd gym in the south part of Eterna City.
The first gym in Pokemon diamond is in Oreburgh City
go into oreburgh mine and talk to gym leader
you need to cacth dialga first
Nope
catch dialga the go to sunnyshore
After you get 7 gym badges, he will be at spear pillar.
In Pokemon Diamond, you get Dialga before the 8th gym battle. After you beat the 7th gym, you battle at the peak of Mt. Cornet, Spear Tower, and battle, preferably catch Dialga, then you can access Sunyshore City. In pearl you battle Palkia.
you don't need an ar code for dialga in diamond just follow the story and befor the 8th gym leader you go to mt cornet and get dialga at spear piller
its in sunnyshore city, but you have to catch dialga first. same with pearl but you catch palkia.
U GOTTA HAVE 7 GYM BAGES AND FACE PALKIA OR DIALGA IN SPEAR PILLAR
in diamond you get him at spear pillar after battling the seventh gym and went to veilstone city and defeated them there Pt after you finished the elite four go to spear pillar you cant get dialga on pearlin Pokemon lake you can get him in map 16 with mewtwo and areus
In both games, go to Mt Cornet near the first gym, use rock climb on one wall then go find Dialga in Diamond or Palkia in Pearl.
must have seven badges and went to spear pillar (where u catch dialga) and galatic HQ
You can find the 2nd gym in the south part of Eterna City.