2006 Prius one radiator fan goes into high speed

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Rebuilding prius, Jul 31, 2018.

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  1. Rebuilding prius

    Rebuilding prius New Member

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    2006 Prius. I have been in a minor front end collision, but the fans are running the correct way. When the prius is on without the A/C, both fans run on low. When the A/C is on the right fan runs on high, but the other never does anything. I have not seen them both go on high at the same time. I believe my car is overheating because I press on the gas, and it doesn't move much after driving with a/c on. I turn a/c off, both fans kick on low and I can drive again. I have replaced coolant temp sensor located on the radiator which allowed both fans to run on low. I connected the left fan to a 12v connection and it runs on high....so I know its not the fan motor. I tested FAN RELAY 2 and 3 and both work. All of the fuses under the front seat are fine. CDS fan fuse is fine. RDI 30A is fine. Can someone tell me where fan relay 1 is? I don't see it here. Or any other help would be appreciated.
     

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    #1 Rebuilding prius, Jul 31, 2018
    Last edited: Jul 31, 2018
  2. ITBland

    ITBland Active Member

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    It is listed as part of the "Inner Circuit" of the Engine Room Junction Box (the fuse box).
    upload_2018-9-9_6-49-10.png
     
    #2 ITBland, Sep 9, 2018
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  3. ITBland

    ITBland Active Member

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    Check the 30A fuse labeled RDI, it is fan #1's Full speed fuse. (When running in low speed, both fans use the CDS Fan fuse, in high speed mode, Fan #1 is run independently with the RDI 30 A Fuse.)
    upload_2018-9-9_7-15-39.png
     
    #3 ITBland, Sep 9, 2018
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  4. ITBland

    ITBland Active Member

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    upload_2018-9-9_7-19-56.png upload_2018-9-9_7-20-26.png
     
    #4 ITBland, Sep 9, 2018
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  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    And it is part of Unit C which is one of the integrated relays (4 relays in one case).
     
    #5 Patrick Wong, Sep 9, 2018
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  6. ITBland

    ITBland Active Member

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    Looking at parts online it look like part # 82641-47020 and is a bit pricy (~$115 + shipping), but I don't think I'd buy that used. On eBay I see used for~$30, one seller has new for ~$86
    McGeorge online parts (good people) have it for ~$105 + shipping.
     
    #6 ITBland, Sep 9, 2018
  7. ITBland

    ITBland Active Member

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    The test for the relay is:
    3G pin 2 to 3G pin 3 = 10k ohms or higher (but not open)
    3G pin 1 to 3G pin 4 < 1 ohm with 12v supplied to pins 2 & 3

    Also look for loose connector or burned wires (The other relay on the same connector is the Fuel Pump Relay)
     
    #7 ITBland, Sep 9, 2018
  8. Lojpur

    Lojpur Junior Member

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    Dear friends, I was following these posts because I have same problem with my prius. I have a used relay and I don't know if I'm testing it in the proper way. I'm getting 307 ohms 3g pin 2 to pin 3. I have uploaded a photo so please can you help me to understand if I'm doing it right.
     

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    #8 Lojpur, Mar 25, 2021
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