t800 only blows hot air

Discussion in 'Kenworth Forum' started by Rdbinc, Nov 1, 2019.

  1. Rdbinc

    Rdbinc Bobtail Member

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    My t800 will only blow hot air. I've changed the acutator and the controls in the dash. Still blows only hot. Tried turning the A/C on, compressor kicks in and still hot air only. Any ideas?
     
  2. spsauerland

    spsauerland Road Train Member

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    Coolant flow control valve on passenger side lower firewall.
     
  3. truckdriver31

    truckdriver31 Road Train Member

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    no 134a in it
     
  4. snowwy

    snowwy Road Train Member

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    Technically, the compressor won't kick on if there's not enough freon in the system. Unless it's my truck where the low pressure switch seems to be messed up.

    But yeah. If it's low. There won't be any cold air. Put ac gauges on the system and see what the EQUALIZED PRESSURE reads without compressor running.
     
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  5. stillwurkin

    stillwurkin Road Train Member

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    Have you confirmed actuator is working? May have lost its power or ground. If ac is working properly then only other option is to shut off the valve that controls coolant flow to heater core. Think someone mentioned that already. I had an older truck that didn't have a actuator. It had a valve that worked on a cable from the dash, to control temp in the cab. It would only shut off mayby 90% of hot coolant flow. So my ac didn't get quite cold enough on really hot days. So shutting off the flow completely with the under the hood valve did the job.
     
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