Telstra says phone services should be completely restored in Alice Springs by Wednesday night.

Almost 400 customers in the centre of Alice Springs lost phone, internet and EFTPOS services when a man crashed a car into a Telstra cable box on Gregory Terrace on Sunday.

The company has had 12 people working around the clock to fix the damage.

Mark Sweet, Telstra's general manager in the area, says the crash badly damaged the cabling.

"There's ... well over 1,000 pairs of copper wires going into this and they were snapped off at the base," he said.

"It's not just there where you've got to join it - you've actually got to go further back to the cable and join it there.

"It's a labour intensive and slow, painstaking work."