The top of an engine from an ailing SUV lies in a bewildering scatter of mechanical parts on Andrea Campbell’s work bench. Outside, a pickup truck with a brake line issue awaits, and after that another vehicle with an engine that is misfiring.

“Everybody’s got something different here,” said Ms. Campbell. “Old Island beater to fancy car that comes in once a year.”

It is all in a day’s work. She fixes them all.

Except these days it’s a little different. After working for many years as a mechanic for McIntosh Motors on West Tisbury Road in Edgartown, Ms. Campbell has stepped into an ownership role. When Bruce McIntosh decided to close his business, Ms. Campbell decided to open her new business, Andrea’s Auto. She bought the parts, the tools and the equipment, and leases the space now.

Mr. McIntosh is still around, he’ll help her get started with the new business, but she’s the boss now.

Andrea Campbell started working on cars when she was in the Navy.

She said owning her own repair business never entered her mind when she first got the job at McIntosh Motors. In fact, she was laughed at when she applied for a mechanics position at a few other Island establishments. But after several years of persistence Mr. McIntosh hired her.

“I was so happy to have gotten a job, that was it,” said Ms. Campbell. “I was just ecstatic to be able to work on the cars. To be able to actually do the work, I was so happy, that was enough for me.”

Over the years, she gained experience and responsibility, and it all started to make sense.

“The last couple of years Bruce started to ask me to take on a little bit more,” said Ms. Campbell. “So a little at a time I did that, and then he started hinting, would you ever want to do this? I never would have had the opportunity otherwise, if it weren’t for him. He changed my life.”

She credits another mentor with sparking her interest in auto mechanics.

After graduating from Norwich College, a military school in Vermont, she joined the Navy, where she received training as an engineer, and was assigned to the U.S.S. Kearsarge, an 844-foot amphibious assault ship.

“I had a senior chief who was probably one of the only people who saw I was taking my job seriously,” said Ms. Campbell. “Most of the other people were not super thrilled that I was there. He knew I was willing to put in the work. So every time we were on shore he would take me to his house and show me the practical aspect of working on cars. I just had it in my mind someday I would really like to do that.”

Ms. Campbell concedes that starting a new business is a bit daunting. She says she has a very long to-do list at the moment that involves tax numbers, bank appointments and business plans, in addition to spark plugs, alternators and brake pads.

There's a new auto repair shop owner in town — her name is Andrea Campbell. — Ray Ewing

“I’m definitely very nervous, being a female shop owner, it’s a daunting thing for me. I know that I can do it, and I know that I have been doing it. It’s just, I’m a little wary of it.”

Ms. Campbell is eager to share her knowledge of automobile repair and maintenance with other women. She teaches classes at Adult Community Education (ACE) Martha’s Vineyard. Women, and lately a few men, take her course to learn how vehicles work, and how to talk to the mechanic when it doesn’t work.

“I wanted to give women the feeling they could come in ask any question and not feel stupid, and not have any guys in here to make them feel self conscious about it,” she said.

She also is free with advice on how to take care of vehicles. She says too many people wait until a part is about to fall off before they bring the vehicle to a garage.

“In most cases all you’re doing is adding and adding, and the cost goes up and up and up. It goes from one part to the next down the line. Say you get a noise in your wheel when you turn. It starts out only being one thing, and the longer that one thing is out of balance, you’re going to go to the next piece down the line, then you’re going to replace the tire.”

Ms. Campbell has long since proved her value as a successful auto mechanic, but she still encounters people who are taken aback when they find out she will be working on their vehicle.

“I do still encounter that,” she said. “It seems to be a little bit less. When I first started, there was a lot more.”

Oddly enough, she said, she runs into a few women who don’t much like the idea of a female mechanic. Some went so far as to refuse to speak to her when they came to the shop before.

“It will be interesting when they come back this summer, and they say where’s the boss, and I say, right here.”