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Komatsu pc128 won’t start

Jjkg1990

New Member
Joined
Jul 15, 2020
Messages
1
Location
Hawaii
My Komatsu won’t turn over. When I turn the key one everything come on. The only way it will turn over is if I connect a ground wire to the alternator and ground it to the machine. After it starts I can pull the ground wire and the machine will run fine. Changed the safety starter relay. New alternator also. Power going to the alternator. Any help would be helpful. Thanks
 

John C.

Senior Member
Joined
Jun 11, 2007
Messages
13,184
Location
Northwest
Occupation
Machinery & Equipment Appraiser
There are Dash numbers on the end of the model number that we need. The case of the alternator is supposed to be grounded all the time anyway. Unless the engine or machine won't shutdown, why not just put a permanent wire on and be done with it.
 

heymccall

Senior Member
Joined
Feb 19, 2007
Messages
6,142
Location
Western Pennsylvania
I'd search for a broken ground strap from the lower engine block to the main frame.
I believe I circled it. Bellhousing (counterweight side) to frame below. Screenshot_20200715-141615_Chrome.jpg
 
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