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Cummins L10 Haul Truck

TPequipment · 2022-02-04 21:05

I have a haul truck that has an cummins L10 motor in it and the fan will not automatically engage and disengage. At the moment to I have to manually engage the fan clutch by a switch in the cab. Does anyone know where the fan switch is located or if the below picture is it or if this is just a high lo coolant sensor or not

Replies14
  1. #1Coaldust2022-02-04 21:30

    Hello fellow Cummins enthusiast, The L10 uses a signal from the PCM to control the fan. It doesn’t have a dedicated fan control temp sensor. Does your temperature gauge work? Any fault codes? Doesn’t mean someone didn’t reconfigure it, or bypass the PCM , since that product is very long in the tooth.

  2. #2TPequipment2022-02-04 21:37

    no fault codes gauge works fine…it’s in a 91 international

  3. #3Truck Shop2022-02-05 01:41

    1991 L10 with PCM? This is a LTA 10 1991 all manual.

  4. #4Truck Shop2022-02-05 01:44

    Should be a Kysor two or three pole switch on it.

  5. #5TPequipment2022-02-05 04:34

    Yeah I don’t think this truck has a pcm on it…my fuel pump is manual

  6. #6Truck Shop2022-02-05 07:23

    The switch in your photo does it have a connection on it? If so check for power and run a jumper across it.

  7. #7TPequipment2022-02-05 20:15

    The wires are seal and it’s a 3 wire connection one is grounded to the motor

  8. #8Truck Shop2022-02-05 21:16

    The other two have a connector plug some where in line. Use some steel wool in the metal base part of that switch. If it is a temp sender for the fan there should be name and numbers on it. But the letters NO or NC normally open or normally closed will tell you it is the fan switch. Plus that could be a three pole grounded fan switch and where it's located is correct.

  9. #9TPequipment2022-02-05 22:14

    ok I’ll look tomorrow and see if I can find some sort of number on that switch and see what comes up…I know the other two wires go into a bundle I’ll have to cut it open trace them

  10. #10TPequipment2022-02-08 20:04

    So found part number on the switch turns out it IS the fan clutch switch suppose to kick on at 205…so I decided to let the truck run up to 210 and fan still won’t kick on but when I tried to manually turn the fan on when it was at 210 it would not kick on but after the truck cooled down below 205 I was able to kick the fan back on manually…so my thoughts are now that whenever they wired the manual fan switch into the cab they swapped some wires around the wrong ways because I think the fan switch sensor is working but when it kicked in (above 205) it killed my power from manual switch in cab

  11. #11Truck Shop2022-02-08 20:41

    Does that truck have working A/C?

  12. #12TPequipment2022-02-08 21:27

    No sir

  13. #13Truck Shop2022-02-08 21:54
  14. #14TPequipment2022-02-08 22:01

    thank you