A fault in the electric system for Tucson’s modern streetcar left city officials with the 65-foot-long road hazard stuck on the tracks during a system test late Tuesday night.

Eventually, the electric vehicle was towed back to the Sun Link Maintenance & Operations Facility after the failed first test of the overhead electrical system powering downtown’s newest form of public transportation.

City officials downplayed the system not having enough juice to power the blue-and-silver-painted streetcar, citing a tripped electric breaker that wasn’t installed correctly.

The problem found while testing a portion of the 3.9-mile track on North Fourth Avenue wasn’t surprising, said Andrew Quigley, a project manager for the city of Tucson. “This is why you test” Quigley said.

Officials did not have the equipment to fully test the system until the first modern streetcar — dubbed “101” by the city — was delivered last month.

The city can perform only partial load tests of the electrical system until the second car is delivered and available for testing.

Another vehicle is not expected to be ready for at least another month.

The issue was discovered on the second consecutive night of on-site tests on the system of the nearly four-mile track linking the University of Arizona Medical Center campus to downtown Tucson.

Quigley said the issue would not delay future testing of the streetcar, which is set to resume next week.

The two nights of testing found some minor problems with the overhead transmission lines, Quigley said, requiring minor adjustments to their positions.

These issues are bound to come up as the city begins to test the system, said Councilman Steve Kozachik, a frequent critic of the modern streetcar.

“They will find more issues,” he predicted. “This is to be expected. ... This is the beginning of the test period.”

The $197 million project is considered to be financially “on track,” but the delivery of the electric vehicles is almost a year behind schedule.

The last car will be delivered next April, with a new car arriving every four weeks.

Barring any other significant delays, the streetcar could be up and running by next summer.

Contact reporter Joe Ferguson at jferguson@azstarnet.com or 573-4346.

Follow him on Twitter @JoeFerguson