He SHOULD be in the power plant. You try to go inside and he bumps into you. He goes to the gym. Then you must go to the gym and he says where the part is (Top left swimming rings)
You have to battle him in the cerulean gym.
Some random rocket grunt.
it's found in the Cerulean Gym where you face Misty. (found in a pile of inner-tubes after facing a couple of rocket grunts on the left side of the gym.) One rocket grunt will be found in the cerulean gym, and another on the bridge leading to the Cerulean cape. You must beat both of them to recover the lost power plant part though.
I'm pretty sure that the Rocket Grunt does not immediately show up in the Cerulean Gym. He should be stirring up trouble on the Nugget Bridge (north of the gym). Talk to him there, and he'll battle you. After beating him, he should run away. THEN you should be able to find him in the Cerulean Gym, and there he will give you the part for the Power Plant. (It's been a while, and I played SoulSilver, but in any case this information should be correct)
theirs a scientist in a room you go to the left of him and there is a grunt you have to battle him then there's a different scientist you have to battle him i already beat th game ]={
You have to battle him in the cerulean gym.
Go to Cerulean City and go to the bridge in the north. He's between some couple and if he's not there you have to go to the power plant southeast of Cerulean in order for him to appear.
After they broadcast there comeback on the radio tower, the rocket grunt will be gone.
You can't find team rocket anymore after the one grunt in Cerulean city.
nugget bridge
in heartgold, if you are in cerulean city, you must go into the gym and go around every thing and the machine part will be in the inflatable tubes i think it will work in Soulsilver as well
Some random rocket grunt.
In Pokémon HeartGold and SoulSilver, you need to find the stolen MachinePart and return it to him. A Team Rocket Grunt stole it and stashed it by one of the life rings in the Cerulean Gym.
You must get the missing piece from the team rocket grunt in Cerulean city.
The thief, a Team Rocket grunt, should be in the Cerulean Gym. Follow him up to the Nugget Bridge, battle him, and then return to the Gym and poke around the inner tube stacks. The Machine Part should be hidden there.
Get the machine part from the team rocket grunt at ceruleun gym.
I believe he is hiding on that yellow bridge in Cerulean city.