8
MTH SD40-2 Diesel Operating Manual
the air lines coming apart. It can best be described as a CHA-CHUSHHH
sound. The coupler doesn’t have to be fired in NEUTRAL. Once the
coupler is armed it can be fired in Forward, Neutral or Reverse. However,
you may find that the coupler
doesn’t open when firing the
coupler at high speeds. Reduce
the voltage setting on your
transformer if this occurs and
run your engine at a slower
speed before firing the coupler.
If the coupler continues to open
erratically, try lubricating the
knuckle with light oil as
indicated in Fig. 3.
For multiple heading purposes, only one of the two ProtoCouplers™ will
function at any one time. Use the coupler direction switch as shown in
Figure 3 on page 17 to select either the front or rear coupler. Simply slide
the switch toward the direction of the coupler you want to make active.
NEUTRAL-ACTIVATED CAB CHATTER SOUNDS
Your engine is equipped with four dispatacher-to-engineer “Cab Chatter”
radio transmissions that occur every 2 to 30 seconds. Each sequence will
play at random intervals to eliminate repetition. While the sounds are
selected to play randomly by the microprocessor, there is no guarantee that
you won’t hear the same message repeated twice or more times.
SQUEAKING BRAKE SOUNDS
ProtoSound® equipped engines feature the ability to play the sound of
squeaking brakes whenever your engine slows in speed. There are two
settings for activating the squeaking brake sounds. The default setting
allows the brake sounds to play while the engine is in forward or reverse
and the transformer throttle is lowered from a high setting to a low setting
(14 volts to 8 volts or less). The
second setting requires that a bell
button be used to “arm” the
brake feature and is explained in
more detail in the “Activating
Freight Yard Sounds” section
Lubricate
ProtoCoupler™
Knuckle
Figure 3: Lubricating The ProtoCouplers
Squeeek
Throttle Down From
High Voltage To Low
Listen For The
Squeaking Brake Sounds
