The striker has mainly been restricted to substitute appearances for his parent club this season and is relishing the chance for more regular first-team action.
He told the club's official website: "It will be nice to give whatever I can give to help the boys out and try and get them promoted.
"I don't know about looking beyond these six games - people might say I've got something to prove but all I'm doing is looking forward to getting back in and enjoying my football.
"The manager has just told me he wanted to come in and boost the squad. He wants the team to get promoted and so do I. I will give anything I can to help out."
Meanwhile, Wolves' chief executive Jez Moxey is confident Mick McCarthy is happy with the pre-deadline signings of Harewood and goalkeeper Graham Stack.
Moxey told the club's official website: "We asked ourselves if there was anything else we needed to do before the deadline closed and we are happy with the business we've completed.
"Marlon's signing was something Mick was very keen to do when we became aware of his availability and we're now relieved to be back to three goalkeepers after Darren Ward's injury problems.
"Mick was always very comfortable with his squad, but this is such an important run-in we wanted to make sure we had all bases covered and I think we have done that."