Stuffed with sensors, high-tech engines and electronic systems, the cars running on U.S. roads are about as good, and as complicated, as they ever have been.

But guess what happens when something does break?

Barely enough mechanics are available to take care of all the cars and trucks in the country.

“I think crisis is a good word for it,’’ said automotive analyst Harry Hollenberg of Carlisle & Co., a consulting firm near Boston that recently surveyed 22,000 vehicle technicians nationwide.

After selling almost 70 million new vehicles over the last four booming years, the nation’s 17,500 new-car dealerships face a curious predicament. Auto sales finally have slowed, leaving dealers ever more dependent on the service department for profits, even though many are short on employees.

More:Moore Tech and Memphis car dealers plan auto tech school

“It’s very difficult to get workers,’’ said Nora Boyte, chief financial officer of Mid-Tennessee Ford Trucks, a Nashville dealership. “We could use three people right now. We’re willing to train them up.’’

As many as 25,000 jobs are vacant at dealerships throughout the nation, Mark Davis, automotive programs manager at Seminole State College in Sanford, Fla., told the New York Times in April.

Dealers must recruit from the same small pool of trained workers as other employers, including independent garages and factories. The problem is too few skilled people available in the labor force as baby boomers retire. Adecco Group North America, a recruiting firm based in Jacksonville, Fla., estimated 62 percent of companies throughout the nation in an array of industries struggle to replace skilled workers.

“Coming out of the recession, a lot of dealers were just trying to survive. Then they had the quick rise in sales and were just trying to meet demand. Now as sales plateau, people are looking at the operational aspects of their dealerships,” said Steven Szakaly, chief economist at the National Automobile Dealers Association, a trade group in Tysons, Va.

Wage inflation

Charles West, owner of the Knoxville dealership West Chevrolet, said wage inflation appears likely after the area’s hiring binge depleted the number of skilled workers for all industries. Following a gain of 38,000 jobs since the recession faded in 2009, metropolitan Knoxville’s jobless rate measured 4.1 percent in June, a low last seen two decades ago amid the largest economic expansion in U.S. history.

New automotive technicians now start at about $15 per hour in the Knoxville area, though those wages could near $20 in the next few years as dealers compete for workers, West said.

Hourly wages for all service technicians across the nation averaged $29.70 last year, a rise of $1.64 per hour in two years, says a dealership workforce study by the National Automobile Dealers Association.

In Memphis, where top mechanics can earn $100,000 per year, auto dealers have banded to form their own school for automotive technicians.

Memphis school

Last October, the 54-member Greater Memphis Automobile Dealers Association launched an annual car show as a fundraiser to cover the cost of a school to be managed by William R. Moore College of Technology, a private vocational school in the city. Officials plan to open the school late this year.

“We could place a hundred qualified trainees right now in jobs,” said Memphis dealer association president Kent Ritchey, head of Landers Automobile Group in Memphis.

Memphis dealers set out to replicate Florida’s Seminole State College model and partner with existing automotive programs at Southwest Tennessee Community College or state-funded vocational schools.

But as the dealers met with Tennessee education officials, Ritchey said, they realized the limits of the state-run programs, particularly the outdated classroom equipment.

Engine technology now advances every few years, Ritchey said. So graduates of Southwest Tennessee, for example, still need training on dealers’ modern equipment. Dealers could make do in the past by retraining community college grads. In an era when high schools tend to steer their able students to four-year colleges, however, too few Memphians seek training for blue-collar jobs.

Last year, the community college in Memphis enrolled 8,327 students and counted five auto technicians among its 764 graduates in 2016, according to the National Center for Education Statistics.

‘’The state programs just didn’t give us the control we wanted or the ability to have the amount of input we wanted to have,’’ Ritchey said. “The classes weren’t big enough. And they couldn’t move fast enough or generate as many qualified people in the pool as we are going to need.’’

Recruiting workers

Although automakers rely on dealers to sell their vehicles, manufacturers and dealers are separate businesses. Other than providing training sessions to explain new technology, automakers have handed dealers the task of finding and educating mechanics.

Factories and dealers compete now in the same shallow pool for workers. Dealers often comb through oil-change shops for workers. Some offer starting bonuses or, most often, rely on a satisfied mechanic to tell others of open jobs. Once a new worker starts, dealers take on the training cost, often by starting a new recruit on the oil-change line and gradually pairing them with an experienced mentor.

“The biggest success we’ve had is just growing our own,” said Steve Dingus, service manager at Wallace Imports, a Kia, Subaru and Volkswagen dealership in Bristol, Tenn.

Once a daughter might have watched her dad rebuild a carburetor like a jig saw puzzle. These days, the simple mechanical puzzles have given way to complicated fuel injection systems.

“No one tinkers with cars anymore,’’ said Henry Hollenberg, a founding member of the consulting firm Carlyle & Co. in Concord, Mass.

Consequently, few people seek out a career as a mechanic. Many who do are unaware of the time it takes to become a top-notch technician.

“We’re lucky because our turnover is low. There’s a different generation coming out to the working world now,” said Shelby Boyte Cunningham, business manager at Mid-Tennessee Ford Truck.

Auto tech complaints

Dealers may have to adjust in ways they never had to in the past. When Carlisle & Co. surveyed 22,000 auto technicians nationwide, pay complaints were rife in every part of the country.

“Most people were pretty upset,” Hollenberg said.

Consumers last year paid $34,077 for the average new vehicle, 2.7 percent more than the year before. Aware the transaction prices have been rising for years, discontented mechanics know their pay has not risen as fast. On Aug. 1, Auto Mechanics Union Local 701 in Chicago voted to strike dealerships. The nearly 2,000 members want apprentices promoted after five years.

Hollenberg said his national survey noted auto techs feel unappreciated. Many see showroom sales staff get bonus pay while technicians are constrained, he said. For example, even if they learn to do a 90-minute brake repair in 60 minutes, they are not always paid for their performance.

“Once they get in it a lot of them hate the job and quit,” Hollenberg said.

Overload?

Although auto techs see car prices rising, dealers are not necessarily making more money. Profit margins have narrowed for the typical dealer. Last year, the national chain AutoNation pocketed about $1,650 on every new auto sold, compared to about $1,900 in 2013, reports Henderson Hutchinson & McCullough, a Chattanooga accounting firm with a large practice in auto dealerships.

Rising vehicle prices trace to consumers buying more well-equipped pickup trucks and sport-utility vehicles and financing the vehicles with low-interest loans and leases.

“The industry has been giving the new cars away and making money on the financing and interest,’’ said Travis Flenniken, an advisory manager at the Chattanooga firm. “Now we’re getting past that cycle.”

Now sales volumes are easing. Dealer have to count on their service departments for a larger share of the profits.

“Dealers aren’t scared of an overload of cars and trucks coming into their service departments,” Flenniken said. “They are worried about finding enough people to work in the service departments.’’