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2003 Town Car - always on radiator fan

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    2003 Town Car - always on radiator fan

    2003 Town Car 40k Miles the one I bought from FL. Radiator fan always on. Hvac off, fans running at low speed. AC on, fan stays same speed. This fan is always on - I don't get it.

    What should I do to fix this? Should I start by using a test light to see if the PCM is commanding the fan on?
    -Nick M.
    Columbia, SC

    66 Squire, 89 Colony Park, 90 TC, 03 TC, 06 TC, 07 TC (2x)
    03 BMW 540iT, 07 Toyota Tundra SR5 Dbl Cab/5.7 2WD

    #2
    Wild guess, either the relay is melted or the temperature sensor is dinked and it thinks its hot all the time. I think the overheat signal turns on the high speed fan and probably shuts off the AC as well. I think the relay should live inside the under hood fuse box. Try swapping it with another one to see if the problem stops. If so, replace the relay.
    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC grandpa spec white and cranberry

    1984 Lincoln Continental TurboDiesel - rolls coal

    Originally posted by phayzer5
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

    Comment


      #3
      03 should be controlled by PCM all the way using the ECT as the temp sensor. I would check the line coming out of the low speed fan relay to make sure it's not grounded somewhere (the wire that goes from the relay to the PCM). I'll get the EVTM diagram of that crap in a bit.

      Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
      rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
      Originally posted by gadget73
      ... and it should all work like magic and unicorns and stuff.
      Originally posted by dmccaig
      Overhead, some poor bastards are flying in airplanes.

      Comment


        #4
        Nevermind. 2003 is the beginning of the pulse width modulated clusterF! It's totally controlled by the PCM and has no relays which means some trigger is tripped if it's always on. This could be a bad sensor. Check for codes as some of those sensors will not trip the check engine light by themselves.

        Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
        rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
        Originally posted by gadget73
        ... and it should all work like magic and unicorns and stuff.
        Originally posted by dmccaig
        Overhead, some poor bastards are flying in airplanes.

        Comment


          #5
          Ok I'll get the forscan app loaded and check it out. Rhanks
          -Nick M.
          Columbia, SC

          66 Squire, 89 Colony Park, 90 TC, 03 TC, 06 TC, 07 TC (2x)
          03 BMW 540iT, 07 Toyota Tundra SR5 Dbl Cab/5.7 2WD

          Comment


            #6
            If you get codes P1474 OR P0480, here's the diag process from the service manuals I have.
            Attached Files

            Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
            rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
            Originally posted by gadget73
            ... and it should all work like magic and unicorns and stuff.
            Originally posted by dmccaig
            Overhead, some poor bastards are flying in airplanes.

            Comment

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