2006 Freightliner Columbia Daycab no power to A/C Clutch

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Smellfunny, Aug 24, 2013.

  1. Smellfunny

    Smellfunny Road Train Member

    1,376
    901
    Jan 28, 2012
    South Carolina
    0
    No power to A/C clutch.

    Installed new expansion valve and dryer. New pressure switches installed on receiver dryer. New blower fan motor, new thermostat at evaporator, new temperature sensor in the duct system. Checked and/or replaced all fuses and relays related to HVAC system. Running hot wire to A/C clutch will engage clutch, so no issue there. There are no codes in the system for climate control issues. Is there a low air pressure switch that might be bad? The only paper work that I have that shows air switch locations on manifolds does not have the setup like this truck has. There are no air switches on the top of the manifold where most trucks have them.
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. richardj87

    richardj87 Bobtail Member

    31
    9
    Aug 24, 2013
    dsm Iowa
    0
    the 06 Columbia doesn't have a low pressure switch, should have 2 switches on the ac dryer a binary switch(the one with the 3 inch or so pig tail) and a high pressure switch. you can use a paperclip in place of the high pressure switch if the clutch kicks in the new sensor could be bad or the system could be low on freon. It looks like you have checked/replaced most of the electrical parts on the system except for the HVAC controller on the dash
     
  4. Smellfunny

    Smellfunny Road Train Member

    1,376
    901
    Jan 28, 2012
    South Carolina
    0
    Oh yeah forgot I also tried another FCU (Front Control Unit).
     
  5. richardj87

    richardj87 Bobtail Member

    31
    9
    Aug 24, 2013
    dsm Iowa
    0
    any other parts of the HVAC system not working? or is it just not getting power to the ac clutch
     
  6. Smellfunny

    Smellfunny Road Train Member

    1,376
    901
    Jan 28, 2012
    South Carolina
    0
    Everything else is working fine. Just no power to clutch. Does hot wire from clutch go into ECM? I traced it from clutch to driver side of engine until it goes into wiring harness. There are no breaks in the wire up to that point. DDEC 5 engine.

    When I press the button on control unit for A/C I can feel the relay clicking and I see it working in prolink. I did try a new relay there anyway but no change.
     
  7. pop's

    pop's Light Load Member

    54
    16
    Feb 3, 2013
    Yulee FL.
    0
    I had one drive me nuts. Turn key on no power to clutch the a/c will not have power if the air press. is low. There is a low air press. switch in the dash.
     
  8. richardj87

    richardj87 Bobtail Member

    31
    9
    Aug 24, 2013
    dsm Iowa
    0
    pulled the wiring diagram when I had to run into work today. Looks as if the power wire comes from the AC clutch relay through a bulkhead fitting on the firewall through one of the switches on the ac dryer to the ac clutch and then to chassis/frame ground
     
    Smellfunny Thanks this.
  9. pop's

    pop's Light Load Member

    54
    16
    Feb 3, 2013
    Yulee FL.
    0
    did you ever find the problem with no power to clutch? I have one driving nuts..
     
  10. Smellfunny

    Smellfunny Road Train Member

    1,376
    901
    Jan 28, 2012
    South Carolina
    0
    Nope. The ECM went out on the truck and they replaced it and A/C worked after that. But I am not certain if anything else was done to the truck. It had a detroit with DDEC 5 ECM.

    A different shop put ECM on up the road.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.