Tripac APU Issue

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Silverbeard, Jul 20, 2022.

  1. Silverbeard

    Silverbeard Bobtail Member

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    Houston TX
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    Good morning.
    I just started a new job and got into a 2017 Kenworth truck that has an APU (Tripac) system. This is the first truck I've had with an APU system so hopefully my question isn't completely dumb.
    I've had to do some troubleshooting to figure out how to use the thing because I could never get it to work at all. Finally figured out how to do the reset and get it to crank up but it never stays cranked up. It will kick on and engine cranks right up but runs about 30 seconds and shuts off with the ENG code and trips the reset button back out. I've read some other forums but haven't found a solution. Hoping y'all can point me in the right direction because I'm in south Texas and it's 759 degrees outside. Help!!!!
     
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  3. Dave_in_AZ

    Dave_in_AZ Road Train Member

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    Is it one with a DPF filter?

    Sounds like it's tripping the overload when the compressor kicks on.

    This could be as simple as the two leads going to the compressor aren't making good contact. Take the cover off, unplug said leads, and make sure they aren't grounding to anything and are making good contacts.

    Or your compressor or alternator could be roasted. Or something is rubbing in the harness.

    Typically what happens with these is the engine lasts forever. It's the stuff that's bolted to it that goes south after awhile.

    You basically replace everything, except the engine, then you're good for about 3 years.
     
    Last edited: Jul 20, 2022
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  4. mem

    mem Light Load Member

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    Check the coolant level if you haven't, I have a coolant leak I haven't attended to yet and it does exactly what yours is doing when it's low.
     
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  5. Silverbeard

    Silverbeard Bobtail Member

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    Houston TX
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    No def connection that I'm aware of but I haven't really dug that deep....
    So basically check everything haha....
    I appreciate the reply. I'll start from there and work my way back. I've heard about 50 different ideas on this issue so I guess a process of elimination is the way to go....
    The truck was previously driven by a kid who didn't maintain a #### thing so I'm having to clean up his crap. I hate dealing with shop mechanics and the hassle than sometimes goes with it. I know how to turn wrenches so I'd rather try to fix it myself if it's within my limits.
     
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  6. Dave_in_AZ

    Dave_in_AZ Road Train Member

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    It doesn't use DEF. But some have a DPF. There would be a light on your dash and a rocker switch for regen if it does.

    Check the two leads going to the compressor.

    There are also fuse in that box with the reset switch.

    A popped fuse will also cause this issue.
     
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  7. bigdad7

    bigdad7 Road Train Member

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    As will fuel pump...the fuel bowl low oil and broken wires anywhere

    I have 7 tripacs
    3 dynasis and one carrier the carriers are hell
     
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  8. Dna Mach

    Dna Mach Road Train Member

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    It’s your PCF fuse. It’s a 15 amp mega fuse located in the fuse compartment. Look under your bunk and you’ll see a fuse box with a diagram on it. It’s in there. You can get them at any truck stop or auto parts store. In a pinch an owner op will give you one.

    This fuse is for a fan located inside the TK unit. It will crank up and run on a low setting in cool weather but anymore than that or on a hot day the unit will cut off. Mine tends to blow this fuse every few months. I carry a few spares.
     

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  9. tiddlytanker

    tiddlytanker Light Load Member

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  10. truckdriver31

    truckdriver31 Road Train Member

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    Check coolant lines. Make sure the valves are open. Sometimes the shops will close them to service or repair the truck. Also see if it stays running on fan only. If so then its a ac issue. Those alt go bad all the time. Mine gets belts, alt, water pumps, and ac compressors all the time
     
  11. reeferwrencher

    reeferwrencher Medium Load Member

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    As stated check oil,coolant and shutoff valves also check the rad fan (precooler fan)on the side of the unit.Turn it by hand,make sure it isn't seized if it isn't make sure its turning on if not check for power if no power check for blown fuse as other poster said.
     
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