Combination Meter and HVAC Out

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ScubaX, Jan 29, 2018.

  1. ScubaX

    ScubaX Member

    Joined:
    Mar 29, 2005
    484
    1
    0
    Location:
    Redding, CA
    Vehicle:
    2005 Prius
    Model:
    N/A
    Can the combination meter and HVAC be related?

    So they both went out at the same time. The MFD and steering controls still work showing temps, fan controls etc. If I select recirc or defrost etc I can hear the vent parts move.

    So I sent the combo meter off to repair through eBay seller with excellent reviews. He tested the board and it was bad on a couple parts. Repaired it and tested good.

    After installing it, no changes. The only thing working on the combo meter are the indicators for doors open, headlights, high beam, emergency flashers and check engine light. I have no speedometer, odometer, fuel, backup lights, turn signals.

    Any ideas? I have checked every fuse in the engine and dash. I have reseated every connection. The eBay seller has called me and he is looking at ideas and offered to retest it including a thermal test in a chamber.

    Thanks for your help.
     
  2. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    1,783
    608
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    What part of HVAC is not working? If you just mean that blower is not blowing then perhaps that’s just a bad blower and a bad combination meter. Or maybe you just have bad 10A gauge fuse. Or no power to it?
     
    bisco likes this.
  3. ScubaX

    ScubaX Member

    Joined:
    Mar 29, 2005
    484
    1
    0
    Location:
    Redding, CA
    Vehicle:
    2005 Prius
    Model:
    N/A
    As far as I can tell it is just the HVAC blower not running. When I turn up the heat for instance all indicators work and even the engine comes.

    I’ve checked every fuse with a fuse tester and pulled to visually check the most suspected. I have not yet checked power to the fuse. Thanks for the idea.
     
  4. ScubaX

    ScubaX Member

    Joined:
    Mar 29, 2005
    484
    1
    0
    Location:
    Redding, CA
    Vehicle:
    2005 Prius
    Model:
    N/A
    Thank you so much. Even though I checked the fuses I somehow missed the one important 10A gauge fuse, it was blown. HAVC and combination meter are up and running. Now to find the runt version of this Mini-ATC fuse, I used a regular Mini-ATC to test with.

    Again, thanks. I have no idea how my tester missed it or I just skipped it by mistake.
     
    bisco likes this.
  5. ScubaX

    ScubaX Member

    Joined:
    Mar 29, 2005
    484
    1
    0
    Location:
    Redding, CA
    Vehicle:
    2005 Prius
    Model:
    N/A
    Update.

    Fuse keeps blowing with repaired combination meter installed. Once I removed the CM, the car runs fine and the fuse does not blow.

    I wish I knew what came first, the blown fuse or dead CM. The repair shop said the meter did fail under testing the first time I sent it in. I just don’t know if it blew the fuse when I reinstalled it or if it was already blown.

    What I do know is with the CM installed the 10A fuse under the dash marked gauge will blow either right away or after several minutes driving. Without the CM installed, the fuse is fine. Also on this circuit are the HVAC motor, turn signals, and front left power window.

    Is there anything else that would be suspect when the CM is installed and not be the CM? It will be on it’s way back to the repair shop for more extensive testing including thermal on a 10A fuse. I’m wondering if it needs additional load the the HVAC motor would draw?
     
  6. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    1,783
    608
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    10A gauge fuse is really just used for control side of relays and control units. And to power the combination meter. And as everything works with combination meter unplugged? That points to combination meter being the faulty component. Or maybe there’s wire’s near it touching something when it’s plugged in?

    You could just use a amp meter with graphical display (or even just a meter that has ability to store records) to measure the current going into the combination meter to make sure that’s the problem. I have never heard about this problem so regarding this problem used combination meter should be fine if you decide to replace it.
     
  7. ScubaX

    ScubaX Member

    Joined:
    Mar 29, 2005
    484
    1
    0
    Location:
    Redding, CA
    Vehicle:
    2005 Prius
    Model:
    N/A
    Those tests are way over my equipment level:)

    It really does seem to point to eithe the CM or a circuit short that is only associated with it. I have not found anything else that is not working with the fuse removed other than what I listed above.

    I’m going to take it for a drive this afternoon for a longer shakedown before shipping the board off.
     
  8. exstudent

    exstudent Senior Member

    Joined:
    Jul 11, 2009
    2,207
    848
    0
    Location:
    Torrance, CA
    Vehicle:
    2007 Prius
    Cause - Effect.
    CM not installed, did you test HVAC motor, turn signals, and left front window, to verify that these items are NOT blowing the 10A fuse?
    If NO, further evidence of the eBay repair.

    Cut your losses. Talk to Matt, about your problem(s) and just order a properly repaired combo meter, from an established, and reputable business and PriusChat member. Texas Prius Battery Replacement
     
Loading...