Archived from the Tools In Action forum (Milwaukee). This thread is read-only.
My 6527 Super Sawzall died. I would squeeze the variable speed trigger, nothing would happen. The HI / LO switch had no effect. The tool was dead.
The brushes were removed, inspected, found to be good, replaced, the tool was still dead.
The reciprocating shaft moved fine when manually pushed and pulled.
The top half of the red clam shell handle was removed to expose the tool electrics. The only exposed voltages that could be measured are the windings w/ the red and with the yellow wires. I found that there was not voltage on those windings when the tigger was squeezed. Everything else had concealed / protected electrical wires that cannot be measured using a voltmeter w/o disconnecting parts.
A non-contact electrical AC voltage “sniffer” was used. It showed the expected AC voltage on the black wire from the power cord connector to the variable speed trigger switch. Both black wires out of that switch, one to the HI / LO switch and the other to the speed controller did not have AC voltage when the trigger was squeezed.
That “sniffer” test lead me to conclude that the 23-66-1490 variable speed switch was defective. The wires to the switch were disconnected and the switch was removed. Note that the easy way to remove the wires is to insert a small probe into the wire cavity. A jeweler screwdriver works well to release the spring tang holding / retaining the wire conductor within the switch.
Once the variable speed switch was removed, it was disassembled. The disassembly is easy. There is a post on each side of the body. I used a pair of loose utility knife blades to pry the body away from the posts so the switch guts would be released.
When the switch guts are out of the switch body, that reveals a conductive / resistive surface and a wiper that drags across that surface. I used Isopropyl alcohol to clean both the surface and the wiper. All the switch guts parts were replaced at the correct locations and the switch was reassembled.
The tool wiring was restored to original connections, the switch was screwed back into position and power was applied.
The tool now works again!
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[External image (farm5.staticflickr.com), not copied]
[External image (farm5.staticflickr.com), not copied]
[External image (farm5.staticflickr.com), not copied]
I repaired my Catalog No. 6509-21, Model 962D Milwaukee Sawzall today by implementing the above procedure. My saw now runs perfectly! Thanks for the post.
Since this switch is no longer available as a replacement part, I need to “rebuild” the internals. My only problem is that the one side that you don’t have pictured is the side I need to rebuild. It appears to be different from the opposite side. Any chance you have a picture of the third side of the switch?
My tool kept working intermittently. removed the trigger switch and cleaned the gaps between 2 cables after continuity test failed, put it back , it’s working properly.
