Columbia HVAC

Discussion in 'Freightliner Forum' started by whprsnpr, Feb 21, 2020.

  1. whprsnpr

    whprsnpr Bobtail Member

    20
    1
    Apr 17, 2011
    Lake Arrowhead California
    0
    Problem began when cab heater/AC fan decided to run continuously on high, switch on panel had no affect

    Got to a point if I wanted heat it was required I turn on AC button

    Replaced HVAC control module/switch plate on dash

    I now can turn on/off the fan but no heat.
    When I turn on heater I’m hearing clicking from the fuse panel passenger side in front of seat on dash.

    Im thinking it’s a relay that controls opening and closing of the door, which allows heat/cool in the system

    Freightliner is not real good at identifying fuses/relays pertaining to the HVAC systems

    Am I anywhere close on my thinking with regard to the relay ??

    Anyone
     
  2. Mike250rs

    Mike250rs Medium Load Member

    539
    1,912
    Sep 24, 2019
    Raleigh, NC
    0
    I'm trying to remember if that truck has the small fuse box behind the driver seat in the column.

    If so, check the plugs going in & out of the box. Frieghtliner was bad for having the connectors heat up and sometimes melt causing the pins to loose contact.
     
  3. whprsnpr

    whprsnpr Bobtail Member

    20
    1
    Apr 17, 2011
    Lake Arrowhead California
    0
    I’ll check but there are two unmarked fuses on the panel in the dash that are HVAC

    found those functional
     
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