Air channels.....

[Iver]

I noticed on our MC9 that on the driver's side radiator intake compartment, there is a channel which goes forward into the coach.  Was this an original fresh air source for the factory heating system?
  I can't really see where it goes.  I just don't want to lose any air that should be going through the rad.

The engine intake air is on the pass. side of the coach with a vent directly on the outside wall. However, there is a short 4" tube from bottom of the pass. side radiator compartment which tees into the intake air as well.  Not sure if this is original or by the previous owner.
  The air intake on the outside wall is large enough to supply air to the engine so I was thinking of blocking that tube off to keep all air going into the rad.
                Iver.

[NewbeeMC9]

That "channel" on the driver side is the air intake for the engine on my bus.

[Jerry32]

same here

[RJ]

Iver -

The others are correct - the engine air intake is on the driver's side of the coach, in the upper corner of the radiator intake.

If you go to the suction side of the air cleaner and follow the plumbing, you'll see.

The air intake you're talking about on the passenger side is for the fresh air blower that was part of the original toilet's ventilation system.  This was a two-speed blower that ran on "low" anytime the master ignition switch was on, and switched to "high" when a passenger went inside and locked the door to use the facilities.

The air intake for the coach's OEM HVAC is located on either side of the vehicle at about eye level just behind the front axle, over the old HVAC condenser compartment on the driver's side, and in a corresponding position on the passenger side.  Roughly a 4" x 8" grill w/ small round holes.

FWIW & HTH. . .

[Busted Knuckle]

However, there is a short 4" tube from bottom of the pass. side radiator compartment which tees into the intake air as well.  Not sure if this is original or by the previous owner.
Iver.

Iver,
This "T" set up sounds to me like what we used to do to my uncles MCI 9's, 96A3's, and 102A3's. We used to take the toilet vent and hook it into the engine air intake, and do away with the vent fans when the motor went bad or the housing rotted out.
By doing this it had a constant air draw anytime the engine was running.
FWIW  BK  

Not to mention I used to tell my Uncle it also gave him better fuel mileage & performance.

[Iver]

I guess my system has been modified from the original.   My air cleaner is mounted on the pass. side just around where the original a/c compressor was.  The air intake for the filter is just above the side access engine door on the pass. side.

So I guess there is no problem to block off that channel on the driver's side if it serves no purpose any more.
  Thanks,  Iver.