Experienced with a Freightliner Classic..... Need your help

I currently have the same issues. Have all the parts, haven’t fixed it yet. Aside from bunk filter being clogged, or blocked. The fan itself may be weak. Looks the same as dash fan, but is different. Different plug, and maybe different rotation. The bunk fan switch is prone to overheating. Eventually needing to replace the short harness, along with the switch. Aside from having bad air cylinders,in the cab, I think there’s 4 of them. The controller itself leaking. I move the selector, just a bit. For now, it stops the leak The recirculating button controls a door near passenger feet. The intake may be plugged. The air intake is on passengers side cowl, outside. Taking out the blower motor, and cleaning the cab intake, and the coils with degreaser, then again with soapy water or any cleaner, no bleach. Rinse it with a garden hose. It should drain out the drain tube. Unless it’s blocked. Or you can disconnect the heat hoses to heater core, leave A/C lines hooked up. And pull both coils out, and clean them. Either way. Same with bunk. Make sure a/c coil and heater core are clean, an air air gun should do it. On the Cab, Taking off the top of center dash, and the side facing passengers, should give access. The dash itself is the problem, You can loosen it up, but doesn’t give much access, I’ve yet to figure out how to remove the controller, without breaking something. Sometimes, you can take the air lines off the quick connects, cut the end off, and reinstall them. Stopping the leak. Good Luck, it’s frustrating, dash breaks easily. Get a picture from the Dealers parts department. Lists all the parts and locations. Helps a lot. There’s a thread on here somewhere, that has much better descriptions The 4 way “T” is sometimes hard to find. 2- 3 way Ts can be used instead.

 

This why I dread doing anything with the dash or doors or any other plastic part on the truck. Once I take it apart its never the same again.

 

Oh yeah! One thing at a time. Mines been apart for a while. Got a bag full of parts. Lol. It’s time consuming. You might get lucky, Sounds like a good coil cleaning, maybe a new air cylinder or two. Along with slightly moving controller, enough to stop the air leak, till you get time to change it. While you’re in there, disconnect the quick connections on the Axle lock, sliding fifth wheel, and dump valve, if equipped. Cut the end off air lines, and reinstall them. They tend to leak over time.

 

Had a 1999 Classic. One thing to help with the AC I did besides keeping the vents a filters clean was to put hose insulation on the lines running under the cab and sleeper. And also remove the cover from the condenser under the passenger side dashboard and hose of those cooling fins.

 

This is what it looks like. I replaced the skeleton behind the dash valves.
Like I said just a bunch of screws. Haha

 

Good God what a mess. I see you reinforced the parking brake. Mines broken there also. Trying to avoid taking any more apart than I already have. I see new dash frames for sale on eBay. More work.I’d like to remount the parking brake. Bolting it on after the dash is in, making changing it a Breese. Freightliner has too many single point assembly bolts, that hold too many things. Doors are same way. Easy cheap assembly, I guess. Makes for a tough repair. A lot of it could be improved IMO. It all takes time.

 

The metal pieces were to hold the old frame together. The new piece doesn't need it. Changing that and having the ability to install all the dash screws. Sure has gotten rid of a lot of rattles.
Changed the MV-3 also. Fixed the venting and ran some new wire up to the headliner to provide direct power for GPS and dash camera.