The B741 road between New Cumnock and Dalmellington will be closed this weekend, with a 35-mile diversion in place.
Scottish Power work will be carried out on the road, forcing a full closure in both directions.
The road is set to be closed from 7am on Saturday, June 29 until 5pm on Sunday, June 30.
Emergency service access will be maintained, with a separate diversion in place for high-sided vehicles, due to the railway bridge near Coalhall.
A diversion will be in place from Dalmellington, via Ayr Road A713, B742, A70, A76 and vice versa.
The high-sided vehicle diversion will via Ayr Road A713, B742, A70, B730, B7046, U728 ,A70, A76 and vice versa.
More information about the diversion can be found on the Ayrshire Roads Alliance website.
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