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This like new powerful 1/2” Milwaukee 5380-21 corded hammer drill rarely will turn on. When it does, it seems full power. 120volt ac is ALWAYS measured on both sides of both brushes when switch is depressed, but only rarely will it run. It’s completely dead, no click, no hum, no heat, no smoke! Brushes look smooth and almost new. Armature appears smooth, but I have not dismantled. I’m convinced the switch is OK. What’s my problem?
Hi, Have you checked the switch is OK using a meter? Here’s the service parts list for the drill. It has a wiring diagram that shows the wiring coming into the switch and then where it goes to the brushes. You said that there is 120V AC on both sides of the brushes, so for current to flow there needs to be a return path. You have the AC voltage at the brushes, check if the neutral return leg is OK. Looking at the wiring there is a black and white wire coming into the drill and connecting to the switch. Usually black is the neutral so presumably the white will be the active.
