4900 hvac ??

One thing I have heard nothing but good things about, is the HVAC on the Stars.
I have a 4900EX and the HVAC is faultless in my eyes. The fan is a little noisier than some, as it is @4 feet away from me is all. Nothing too bad though IMHO.

Martin

 

Look on the far right of your passengers right foot at the HVAC intake door and see if you can look through the screen. The flapper is closed on the inside of that, it is sucking air from the outside. then if its not there its on recycle (max), and is sucking air from that screen. If its a dusty environment, the cab air filter is plugged after a week. The flat plate to the left of that screen is the filter cover. Turn the heater coolant valves off on the engine that go to the cab and sleeper if it has one.

 

IMHO the a/c system is adequate, but the ducting does not allow for max air flow. i have to run mine on high all the time when its 90+ and humid, as it is most of the summer here in southeast PA. i took my entire system apart when i got the truck and cleaned the dust out of the heater core and AC evaporator. it was clogged solid with dust due to the idiots, i mean previous owners, removing the filters instead of cleaning them. clean your filters weekly with soap and water. they will be filthy in a dump truck environment after a week as previously said. FWIW, if I'm in the truck all day and not constantly getting in and out, it keeps up just fine. it can't keep up when the door gets opened 10 times an hour.

also, i flip my engine fan switch to "on" when i pull into a job site where i will be sitting for a period of time. helps drastically.

BTW, there IS a solution to this problem with the dust. i installed a fresh/recirc button in the "bunk AC" location in the factory ac panel. bought another AC button, made a label, cut out the factory hole in the panel, stuck switch in, and "viola", fresh/recirc just like it should have been from the factory. bypasses the factory recirc location in the panel, allowing you to have recirc in ANY position. wiring is simple. theres three wires going to the recirc door actuator. find the ground and cut it. run that ground to the new switch and then back to the actuator so your switch is simply interrupting that ground. this will move your actuator door to fresh or recirc depending on switch position. i leave mine in recirc all the time and almost never have to clean my filters now. only when i run on site or something where i have to leave a window open in the dust to hear operators or ground men. my dealer recommended i remove the actuator and tie the door to the "recirc" position for a dump truck. i found a better solution.

 

Copying this today Roccon, thank you!
Why WS never put a dedicated recirc switch in is beyond me.....
Been in recirc when its been over 100 out, but my leg get a little warm when it is only blowing out the top vents.

Martin

 

An update.
AC works MUCH better in recirculation mode, with all settings available.
FYI, on a 2009, it is the green wire that needs switching to ground. There are three wires there, but the green is the switched wire. Easiest access is by removal of the glovebox.
I had an extra Carling switch already wired, so just used that.
Many thanks Roccoon31!

Martin

 

I'll forward the suggestion on to the appropriate person in WST Engineering.

 

leftlane, thanks for that update, i couldn't remember the wire color. i installed mine last summer. seems like 10 years ago!

 

Thanks! It is a stupid setup, that has a hard time in the desert etc, when not in the only recirculate mode offered from the factory. Now it seems like I can have cold legs and cabin, and only have the fan on number 2. I got some Carling switches to fill in 2 blanks, and used the one that was not being used (other is strobe light switch). Looks factory, as the OEM switches are Carling as well.

Works a LOT better!
Thanks again for the heads up.

Martin