The Midland Metro is unlikely to be fully open before Tuesday after vandals damaged equipment.
Overhead cables were brought down on Wednesday evening when rubbish bags were thrown onto them.
The line between Birmingham and West Bromwich was still closed on Friday evening.
Travel Midland Metro said it had continued to operate a seven-minute service between West Bromwich and Wolverhampton.
It has also introduced a shuttle service from West Bromwich Central to the Hawthorns.
This service allows customers to link with Central train services to Birmingham Snow Hill.