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Need help with translating Komatsu D57S electrical schematic

James Sorochan · 2022-08-30 11:26

I don’t know much about electrical. Can someone tell me what the rectangle symbols coming off alternator with the v and horizontal line means. There is another one just before fuse box. My alternator is putting out 34 volts. Checked at batteries and have 25.1 volts but the two wires going into fuses have the 34 volts. Had it into rewind shop and tech said regulator is working fine. Not sure how to diagnose. Learning on the fly. Thanks

Replies13
  1. #1Nige2022-08-30 11:30

    They appear to be symbols for the electrical connectors in the harness showing which side of the connector has the pin and which has the socket.

  2. #2James Sorochan2022-08-30 12:02

    Thanks Nige. I’ll start checking for that.

  3. #3James Sorochan2022-08-30 13:51

    One thing I noticed comparing the drawing of the fuse block to what was actually wired is the drawing shows the two wires WB and YR are connected together then attaching to the b post which is bridged to the three fuses. What I found was one wire attached to the top 20 amp fuse and the second attached to the second down 10 amp leaving the centre 10 amp not hooked up. I Jimmy rigged it according to drawing and have 27 volts coming out of alternator now. I don’t know if this is right or not.

  4. #4Tinkerer2022-08-30 14:04

    Those rectangles on the alternator appear to diode symbols showing current flow direction.

  5. #5funwithfuel2022-08-30 14:15

    If the line came straight outta the >or<

  6. #6James Sorochan2022-08-30 14:22

    I don’t see any diodes on the wires. I take it they would have heat shrink on it?

  7. #7funwithfuel2022-08-30 14:23

    No, they would be serviceable plug connectors. Almost like the square fuses.

  8. #8James Sorochan2022-08-30 15:02

    Would these be diodes?

  9. #9mekanik2022-08-30 15:04

    Those look like connectors not diodes.

  10. #10funwithfuel2022-08-30 15:56

    Just to illustrate how a diode is shown in schematics

  11. #11funwithfuel2022-08-30 15:56

    And in answer to your original question

  12. #12James Sorochan2022-08-30 16:33

    Thanks everyone. There. I learned something today.

  13. #13Tinkerer2022-08-30 17:13

    Thanks to funwithfuel's image those are definately connectors. It kinda neat that the two wires cannot be connected incorrectly with those plugs.