How to install a K142-535ss-3 Plug & Play Unit (Air Operated)
This video shows an install on a 1999 Kenworth W900L Shout out to Fine Line Transport in Holland, MI for helping us film this video.
The unit that we are installing is our K142-535ss-3 plug & play system. The OEM cross-reference for this unit is K142-535-1. This unit will fit a 1995 – 2002 Kenworth W900, T800, T600, T400, and T450. To find the plug & play unit specific to your year and model truck, visit our Kenworth HVAC box page.
The K142-535ss-3 includes all the parts needed to install the HVAC box on your truck. The following parts are included:
Step 1 – Begin evacuating the AC.
Step 2 – Remove the air intake ducting.
Step 3 – Turn off valves for the coolant lines on the passenger side of the motor.
Step 4 – Use a pair of pliers to remove the coolant hoses from the heater core. Have a bucket ready.
Step 5 – Remove the plastic cover (3) 10mm fasteners.
Step 6 – Use a T25 Torx bit to remove the reinforcement bracket.
Step 7 – Use a 10mm socket to remove the (4) fasteners from the lid. Remove the lid.
Step 8 – Unhook the blower motor and discard the lid.
Step 9 – In order to remove the airline from the air actuator/air cylinder, press down on the white plastic collar and pull out the plastic tube.
Step 10 – Use a 10 mm wrench and socket to remove the AC lines from the AC bracket.
Step 11 – Grind off the top two bolts that hold the HVAC box to the firewall.
Step 12 – Use a 7/8 wrench to remove the lower AC line.
Step 13 – Use a 5/8 wrench to remove the upper AC line. Remove any other accessories attached to the box.
Step 14 – Use a T20 Torx head to remove the three screws from the glove box.
Step 15 – Use a 13mm socket to remove the (3) fasteners inside the cabin of the truck. After popping off the circled cap, pop the other cap out of the socket extension.
Step 16 – Use a pry bar to help remove the HVAC box from the firewall. Then remove the box.
Step 17 – Clean up the surface for the new box.
Step 18 – Prepare the new shoreline box for installation.
Step 19 – Remove the lid by taking out the four bolts using 10mm socket.
Step 20 – Unhook the blower motor from the wiring harness.
Step 21 – Remove the 3 screws from the blower motor.
Step 22 – Begin to install the box.
Step 23 – This HVAC has a rubber grommet installed in the box. Your truck has rubber grommet installed in the firewall as well. It is easier to slip the wiring harness through the grommet when the grommet is removed from the truck than it is to try to push your wiring harness through the grommet. So we would encourage you to pull that grommet out. This is where the grommet is located and pull that grommet out. Slip the wire through the grommet and then install onto the firewall.
Step 24 – Use a 13mm shallow socket and rachet with 13mm deep socket to snug the top 2 bolts of the heater box of the firewall. Don’t tighten it down all the way yet.
Step 25 – Begin installing the (3) fasteners inside the cab of the truck. Don’t tighten them all the way down as the wiring harness in the air line needs to be squared away first before buttoning everything up.
Step 26 – Reinstall AC lines
Step 27 – Use a T20 Torx head to remove the (2) screws from the dash panel.
Step 29 – Unplug the old wiring harness and plug in the new wiring harness. Remove the old wiring harness.
Step 30 – Remove the (4) T20 Torx screws from the AC control to access the old air line. The old air line is connected between this button and the actuator or air cylinder in the HVAC box.
Step 31 – Remove the old air line and plug in the new air line.
This is the air line that returns back to the HVAC box, press down on the white collar to remove the old line and then replace it with a new one.
Step 32A – Start putting the dash back together.
Step 33 – Finish tightening down these (3) fasteners completely.
Step 34 – Install the reinforcement bracket at the front of the truck.
Step 35 – Finish tightening down the top (2) bolts.
Step 36A – Install the blower motor.
Step 36B – The wiring harness has a black wire and a blue wire with a black stripe. The blue wire with a black stripe is hot and the black wire is ground. Make sure the ground in the truck is connected to the ground on the blower motor. If these are reversed, the motor will run backwards and will not blow very hard.
Step 36C – Install blower fasteners. (3) Phillips head fasteners.
Step 37 – Use a 10mm socket to reinstall the (4) bolts for the lid.
Step 38 – Reinstall air intake ducting
Step 39 – Recharge the AC
Step 40 – During AC season, the coolant valves can remain off. Otherwise, if you need heat, open these valves back up.