It’s understood the electrical fault occurred on the line between Cambuslang and Rutherglen and will affect services travelling to and from Cumbernauld, Dalmuir, Glasgow Central, Larkhall, Milngavie and Motherwell.
ScotRail say the disruption is expected until at least 10:00am.
The rail company said on their website: “Due to failure of the electricity supply between Cambuslang and Rutherglen disruption is expected until 10:00 09/05.
“Train services between Milngavie and Motherwell will be cancelled, delayed or revised.
“Unfortunately we’re unable to run electric trains from Motherwell towards Glasgow at present due to an overhead line fault. Our staff are on site and have identified the fault and are sourcing a replacement part to repair.”
Passengers are being advised to check their journey route in advance.
Valid tickets are also being accepted of First and Whitelaws Coaches.
The disruption comes just days after it emerged ScotRail is facing record fines totally £1.6million over shortcomings in services for passengers.
The penalties follow a weekend of bank holiday travel chaos that saw Glasgow Central station closed because of problems with overhead wires.