Help - Gauge Fuse Blowing

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by wooderson, Mar 17, 2014.

  1. wooderson

    wooderson New Member

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    2007 Prius
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    thanks for any direction in advance.

    Warning, this is a bit long. I tried the search function, but no luck.


    We bought this car a month ago, 2007 US touring model. It had a 15A fuse in the Gauge position (spec calls for 10A there) when we bought it. As of last week it is blowing a lot, I'm hoping for some pointers or past experience with troubleshooting this.

    I've got the wiring diagrams, so thanks to whoever posted those on this forum.

    What we've noticed:
    - First time it happened I noticed my signals weren't working. After 5 minutes of driving I pulled over and turned the car off and on. At that point the Combination Meter went blank. After getting home I found the fuse blown. Replaced it with a 10A fuse, and that blew right away when starting the car. Replaced it with a 15A fuse and it worked for a few trips.

    - While I was away for a week, my wife replaced the fuse 3 times while it blew away from home. (she estimates every third trip) She has found it seems to happen when putting the car in reverse.

    - Today the car is working fine, and I can't replicate the problem.


    What's recently been done to the car:
    - Minor rear bumper damage from hit and run in parking lot. Body shop repaired back bumper. (any wiring go near the bumper that could have a short?)
    - I replaced the HID headlight bulbs with aftermarket bulbs from Amazon.
    - Both front side marker bulbs were out and I replaced them. Previous owner did a mod to the front side marker lights, they just come on with the headlights. Power for this is tapped of the PS HTR relay. Input to an additional relay for marker lights is tapped off the headlights.

    So any pointers?

    Thanks again,
    Alex
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you don't have the full electrical wiring diagram for your model year, and you expect to deal with this problem on your own, it is time to obtain that now, at techinfo.toyota.com

    The 10A GAUGE fuse contributes power to many circuits. It would be reasonable to start by looking at the circuits located near known accident damage, such as taillights, back-up lights and rear window defroster. Here is the full list:

    ABS, TRAC and VSC

    Air Conditioning

    Back–Up Light

    Combination Meter

    Cruise Control

    Engine Control

    EPS

    Headlight

    Headlight Beam Level Control

    Key Reminder

    Luggage Compartment Door Opener

    Multi–Display and Audio System (Built–in Amplifier)

    Multi–Display and Audio System (Separate Amplifier)

    Power Window

    Push Button Start System and Hybrid Vehicle Immobiliser System

    Rear Window Defogger and Mirror Heater

    Seat Belt Warning

    Shift Control System

    Smart Key System and

    Wireless Door Lock Control (w/ Smart Key System)

    SRS

    Taillight and Illumination

    Tire Pressure Warning System

    TOYOTA Hybrid System

    Turn Signal and Hazard Warning Light
     
  3. Mike500

    Mike500 Senior Member

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    I would really suspect one of the circuits in the back that is activated by the back up sequence.

    It would likely be a wire that is rubbing somewhere on the grounded body of the car.

    It has probably gotten worse due to a "sawing" action of the wire rubbing against the grounded body.


    First, I'd unplug the multi-circuit connector to the back and test for continuity to ground with the end components disconnected.

    If you have isolated the offending wire, I's check its routing of the starting at the instrument panel all the way back through the routing in the door sills to the back.

    You can either cut and replace the offending wire or find the place where it is rubbing and insulate it with tape.

    It is very time consuming and labor intensive, but anyone with basic electrical knowledge can do it.

    Good luck!
     
  4. nh7o

    nh7o Off grid since 1980

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    These wire fault finding jobs are indeed time consuming. Many Toyota dealers will just go ahead and replace the whole harness, just to repair the situation. Very $$$. I might start with the section of the harness that goes under the rear hatch. If the back up light wire is the culprit, and you had damage to the bumper, it would seem suspect.
     
  5. wooderson

    wooderson New Member

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    This afternoon, it blew again when I selected reverse. So I'll be starting with that and my multimeter tomorrow. Unfortunatly it is very intermittant.

    Thanks for the list Patrick.

    Alex
     
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