What is this component under the dash??

Discussion in 'Gen 2 Prius Main Forum' started by rkeith3472, Oct 22, 2020.

  1. rkeith3472

    rkeith3472 New Member

    Joined:
    Sep 30, 2020
    5
    0
    0
    Location:
    Alabama
    Vehicle:
    2007 Prius
    Model:
    Two
    What is this component under the dash on the driver side in the far corner? It seems to be white and ceramic with red letters “L O” on the top.

    I thought I had an electrical short because I could smell something burning and my positive battery lead was getting very hot. I used a thermal imager and found that this component reached 170° and was still climbing. It’s obviously bad but I have no clue what it is.
     

    Attached Files:

  2. rkeith3472

    rkeith3472 New Member

    Joined:
    Sep 30, 2020
    5
    0
    0
    Location:
    Alabama
    Vehicle:
    2007 Prius
    Model:
    Two
    It’s not ceramic!! It’s silver metal
     
  3. oldtechaa

    oldtechaa Active Member

    Joined:
    Dec 28, 2018
    301
    188
    0
    Location:
    KY
    Vehicle:
    2008 Prius
    Model:
    II
    It'd be great if you could maybe post a picture that shows more clearly the surroundings, maybe from farther away. It's hard to tell exactly where it is. From what I can tell, it's somewhere right near the defrost vent and sun sensor, am I correct?
     
    PriusCamper likes this.
  4. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    4,927
    1,949
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
  5. rkeith3472

    rkeith3472 New Member

    Joined:
    Sep 30, 2020
    5
    0
    0
    Location:
    Alabama
    Vehicle:
    2007 Prius
    Model:
    Two
    Yes, driver side in the corner near the A post
     
  6. RRxing

    RRxing Senior Member

    Joined:
    Jul 7, 2009
    2,220
    1,513
    0
    Location:
    Long Island, NY
    Vehicle:
    2017 Prius
    Model:
    Three Touring
    Picture looks like it was taken from a junkyard Prius.
     
  7. rkeith3472

    rkeith3472 New Member

    Joined:
    Sep 30, 2020
    5
    0
    0
    Location:
    Alabama
    Vehicle:
    2007 Prius
    Model:
    Two
    It’s not. I got the part removed and found a part number
     
  8. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    10,665
    7,830
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Brake actuator resistor?

    [​IMG]

    Edit: by the way, a resistor getting hot usually doesn't mean there's anything wrong with the resistor. Turning electric power into heat is a resistor's job. If it is making more heat than it's designed to, typically that means the thing it's there to resist for is running longer, or drawing more power, than it's designed to.

    Until now I had never bothered looking in the wiring diagram to see what that resistor is there for. There are two power supply circuits for driving the pressure pump that's built into the actuator. One starts at the 25 amp "ABS -1" fuse and goes through the "ABS MTR" relay. The second starts at the 30 amp "ABS-2" fuse and goes through the "ABS MTR 2" relay.

    The resistor is in the first of those circuits. So it is part of the power supply to the pump motor. I suspect the system uses the ABS MTR relay and the resistor when it needs moderate pumpage, and it adds ABS MTR 2 without the resistor when it needs that extra push over the cliff.



    Do you hear your pump motor running? Does it run extra long or sound extra slow? Possibly it could be locked up; motors can draw a lot of extra current in that condition. Or maybe something is open in your ABS MTR 2 circuit, so starting current is all having to go through the first circuit with the resistor.
     
    #8 ChapmanF, Oct 23, 2020
    Last edited: Oct 23, 2020
    SFO, strawbrad and PriusCamper like this.
  9. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    4,927
    1,949
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Lol, just because he took the dash off doesn't make it a junk yard car? Of course if he gets distracted and never puts it back together... :)
     
  10. Diemaster

    Diemaster Active Member

    Joined:
    Oct 31, 2017
    260
    239
    2
    Location:
    so. cal
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    My first thought was perhaps a Daylight Running Resistor?
     
  11. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    5,031
    2,713
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Huh? And which one would that be?
     
  12. RRxing

    RRxing Senior Member

    Joined:
    Jul 7, 2009
    2,220
    1,513
    0
    Location:
    Long Island, NY
    Vehicle:
    2017 Prius
    Model:
    Three Touring
    From the picture taken through the windshield it looks like some metal exhaust pipes laying on top. My mistake...
     
Loading...