Question about 1989 Ford F 350

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1989 ford f350 a/c heater fan only runs on high, replaced switch ,didn,t help. thanks geo

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  • geo_1 Dec 14, 2008

    thanks to fixya, and neil for provideing the "fix" for my truck heater switch problem, quick too! geo.



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When your heater only works on high it is usually
the resistor unit in the heater passage housing. Look for wires ( about 4or 5 wires ) attached to the
plastic heater housing under the dash. It should
have a screw or two holding it to the housing. Pull
it out and you will see several wire coils. If they are melted or broken then thats the problem. On any switch position except high the power goes through these resistors to slow the fan down. Good luck. Neil W.

Posted on Dec 08, 2008


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