Fuses for mirror and door locks continue to blow when I try to operate them. ..

Discussion in 'Gen 2 Prius Technical Discussion' started by PapaWill, Sep 10, 2019.

  1. PapaWill

    PapaWill Member

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    I have a 2009 that belongs to a friend that I was working on for her... Just doing little stuff to help with her maintenence issues. I had replaced the car speakers and also replaced the driver door panel because it was in bad condition. Then one night, it rained, hard. The next morning, I had this issue described below. 2 Blown fuses.... I have gone through every fuse in the car (under the dash and under the hood) and the only ones that are blown are the ones associated with the mirrors ACC 7.5 amp and door locks DOOR 25 amp WHEN I TRY TO OPERATE THEM. I have to assume these are unrelated events, but I am not sure. The issue seems to have sprung out of leaving the windows down on one rainy night. Also, the lid on the fuse box under the hood was open and the hood up while I was charging. I know.... insane of me. Does anybody know HOW ot chase down these circuits? I have all the wire diagrams and have even REPLACED the BODY ECU but still the same issue. Those 2 items blow when I replace them EVERY TIME! Asking for help!!!
     
  2. dolj

    dolj Senior Member

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    On the face of it, I would think the most obvious thing would be the mirror switch and the central locking switch incorporated into the left side front armrest. Have you opened that up and ensured it 100% dry?
     
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  3. PapaWill

    PapaWill Member

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    I have replaced the driver's side pad from a known working vehicle and still the same result... blown fuses on both the mirror and the door lock...! The problem is apparently deeper and I have checked out wire cluster #1 and #2 and I find nothing anomalous. I am not the greatest at sear hing out electrical issues using a wire diagram, although I DO have them!
     
  4. bisco

    bisco cookie crumbler

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    unfortunately, the only way to find electrical problems is to test the circuits. start with the easiest parts and continue until you score.
    if you can't, it's off to a mechanic.
     
  5. PapaWill

    PapaWill Member

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    OK I took off the door panel because I wanted to look at all the wiring that goes through the door grommet, etc., because THAT seemed like the most reasonable place to start... I replaced the speakers and when doing so, I put a screw into the wire harness that runs right along side the speaker housing.... I know. Silly me. So the locks and mirror are fixed, BUT I still do not have a clock or radio or certain functions related to the MFD... Is it possible with the short that I repaired, I may have damaged the sensitive electronics inside the MFD? I don't have another of the same part number but I did just try replacing the clock, to no avail. All fuses are good. I checked the PANEL and ACC and DOME fuses which are related to clock and they are fine. Anyone?
     
  6. bisco

    bisco cookie crumbler

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    could be a bad mfd, but idk how to test it. are they cheap on eBay?
     
  7. PapaWill

    PapaWill Member

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    New Update: Clock and radio and courtesy lights now working. I tried replacing the MFD, but got the same reults. Here is the process... Although the DOME 15 amp fuse is fine, I reasoned that it must be some issue in the harness between the fuse and clock because the body ECU is fine and all fuses within that are fine. I know this because I just replaced the whole dang body ECU with a used working one....So, I connected a jumper wire from the DOME fuse directly to the B+ end at the clock. To my surprise everything works now! So, the problem is somewhere in between and I am confidant that this I can fix.

    I STILL have an issue with the door locks and fob not locking or unlocking from the outside and get a code B1242 related to the Door Control Receiver. I have not tested the harness but will first install a used part to see if this starts working again after the above mentioned short in the driver door harness.....

    So I am coming down the home stretch! What a work out!!!
     
  8. dolj

    dolj Senior Member

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