Ben Franklin would be appalled.

The underground museum that tells his story leaks in heavy rain. Last month, water dripped through light fixtures onto ramps and staircases, forcing the site to close for three days.

Displays and exhibits that were state of the art when the Franklin Court museum opened for the nation's Bicentennial are now outdated or out of service after more than three decades of use.

And efforts to reinvent the attraction - announced last year - have hit unforeseen funding delays during the nation's economic downturn. As Ben once said, " 'Tis easy to see, hard to foresee."

But National Park Service officials remain hopeful that Congress will approve $6 million this fiscal year toward a proposed $18 million upgrade of the only museum in the world dedicated to Franklin's life and legacy. The Pew Charitable Trusts has already promised a $6 million matching grant and helped raise more than $5 million from other sources.

The first revamping of the Franklin museum, off Market Street near Fourth, would be undertaken as part of a 10-year federal effort - called the Centennial Challenge - that seeks to match $100 million in annual federal dollars with private money.

The National Park Service, which marks its 100th anniversary in 2016, hopes to raise the money for educational, programming and capital projects across the country, including the underground museum. Congressional approval is pending.

"When the museum opened, it had one of the most expensive exhibits the National Park Service had ever done," said Dennis Reidenbach, head of the Park Service's busy Northeast Region and former superintendent of the Independence National Historical Park.

"But is it compelling to today's youth? I think Ben would say, 'It doesn't ring their bell anymore.' Learning styles are different now and we need to do Ben justice. He is the most compelling figure from Philadelphia's past, bar none."

Pew officials want action.

"While the fund-raising from other sources was successful, the federal commitment has not yet come through for the project, despite enthusiastic support from the secretary of the interior, the director of the National Park Service and leadership of Independence National Historical Park," said Donald Kimelman, Pew managing director of information initiatives and the Philadelphia Program.

"Given the long time lag and the pending change in administrations, we are concerned that this project may not go forward. . . . We understand and sympathize with the budgetary pressure in Washington, but remain hopeful that money can be found"

At Franklin Court last week, acting Independence National Park Superintendent Darla Sidles described the site's needs as she walked down a tiled ramp - past a bucket used to catch rain water - to the underground museum.

In one popular display area are handsome paintings, inventions and artifacts that recall the life of Philadelphia's leading citizen - his desk, library chair-ladder and Franklin stove. More than 244,000 people visited the museum this year through October, the strongest attendance figure in the last five years.

But a darkened diorama depicting Franklin's role as a diplomat abroad isn't quite as captivating as it was decades earlier. A posted sign says the display - which cost $200,000 in 1975 - is out of service.

And half the phones in another exhibit that allow visitors to hear famous 18th- and 19th-century Americans' and Europeans' descriptions of Franklin don't work or are missing.

The exhibit "is in dire need of a complete overhaul - new exhibits, new heating and air-conditioning, new bathrooms and new alarms," said Sidles, who visited on a day when faulty fire alarms twice forced the evacuation and closing of the site. "We have some major issues."

One of them is the leaky roof. An internal National Park Service report said the attraction closed from Nov. 15 to 17 "due to torrential leaking of the roof (through the light fixtures). . . . The leaks were not able to be contained by buckets (there were more leaks of a much bigger magnitude than usual) and lasted many days longer than normal (the roof was leaking 3 days after the rain stopped!)."

The idea for the underground museum arose in the early 1970s after it became clear that the National Park Service would not rebuild Franklin's stately, three-story brick house - the only one he ever owned, "a good House contrived to my Mind," as he once said.

Without enough information to do an accurate reconstruction, a steel skeleton was raised at the site in 1976 to mimic house outlines.

Below ground, the Park Service built a 7,000-square-foot museum that may - with the proposed $18 million upgrade - eventually become a "virtual house museum," making a clearer connection with the ghost house above.

Visitors to the updated facility would enter a kitchen, parlor, bedroom and workshop, representative of rooms that Franklin may have used, and find artifacts and documents related to that space's function.

The museum may include interactive multimedia presentations and provide information on what was taking place during Franklin's time - and how world leaders of the time viewed him. The new museum also could have a gift shop and cafe.

There's one obstacle: funding. "There are three faithful friends," Franklin said, "An old wife, an old dog, and ready money."

The National Park Service has been looking for the latter with some diligence, which Franklin called "the Mother of Good Luck."

"He spearheaded several civic improvements," said Stephen Sitarski, chief of interpretation and visitor services at Independence National Historical Park. "Since this is a public museum, he would have been helping us."

How far would Ben go to get the funding?

"He would be very active and outspoken and make the noise he had to make to drive the point home - and get the financial resources to do the job," said Bill Moore, president of the Independence Visitor Center Corp., which would develop and administer the new Franklin museum.

"There is a lot going on in the federal government. Whether we can break through the clutter is unclear, but I am cautiously optimistic."

Moore said the museum's needs were so great that "it would be almost better to close it than to leave it open."

The Pew Charitable Trusts has worked to make sure that doesn't happen.

"Benjamin Franklin was one of the most fascinating and important figures in American history and Philadelphia was his longtime home," said Pew's Kimelman.

"A renovated museum, with dynamic new exhibit space, would not only educate the public about Franklin's life, but provide tourists yet another reason to travel to and spend more time in Philadelphia."

Contact staff writer Edward Colimore at 856-779-3833 or ecolimore@phillynews.com.