Garmin 3 Plus Manual

							1
GETTING STARTED
Unit Features
Antenna
(detachable)
Function Keys
LCD Display
Battery Door
Rocker Keypad
Power/Backlight 
Key (red)
To change the screen 
orientation, press and 
hold the PAGE key. 
						

							2
GETTING STARTED
Keypad Usage /  Display
 (POWER)— Red key turns the unit on and off, and 
controls three levels of screen backlighting intensity.
 ( P A G E )— Scrolls main pages in sequence and returns 
display from a menu/options page to a main page. Press 
and hold this key to change screen orientation.
 (MENU)— Displays a menu of available options for 
the current page. Press twice to display the Main Menu.
 ( G O T O )— Displays the GOTO waypoint window, 
allowing you to select the destination waypoint. Press 
and hold this key to activate MOB feature.
 (ENTER/MARK)— Activates highlighted fields and 
confirms menu options and data entry. Press and hold 
this key to mark present position as a waypoint.
 (QUIT)— Returns the display to a previous page or 
restores a data field’s previous value. 
 (IN and OUT)— Allows you to zoom in/out through 
24 scales on the Map Page. Also adjusts scale on the 
Highway Page.
 (ROCKER KEYPAD)— Controls the movement of 
the cursor, is used to select options and positions, and 
to enter data. DATA ENTRY— Entering data, such as waypoint 
names, typically begins and ends with the ENTER/ 
MARK key. Use the rocker keypad to enter the actual 
data: UP/DOWN to change the highlighted character, 
RIGHT to move on to the next character.
CURSOR— A solid black bar which can be moved 
up, down, left, and right with the keypad to select 
individual fields on the display.
 FIELD— The location on a page where a group of 
characters or option is entered and displayed.
 HIGHLIGHT— The act of using the cursor to select a 
field for the purpose of entering data.
 SCROLL— The act of moving through characters or 
options from a selected field.
 DEFAULT— A system-selected format, built into the 
operating software or the unit’s memory, that will be 
followed unless the user chooses a different setting.
Pressing UP or DOWN on the ROCKER 
KEYPAD changes numbers and letters.
Pressing LEFT or RIGHT on the ROCKER 
KEYPAD moves the cursor along the line 
or to the next line.
Cursor 
						

							GETTING STARTED
Batter y Installation
3
The GPS III+ operates on 4 AA batteries (not included), which are installed at the 
base of the unit. These batteries provide up to 36 hours of continuous use (See page 
87). Rechargeable NiCad or lithium batteries may also be used.  
NOTE: The on-screen battery level indicator is calibrated for alkaline batteries, 
and will not be accurate when using NiCad or lithium batteries (see page 77).
To install the batteries:
            1.  Flip up the metal ring at the base of the unit, and turn the ring 90° counterclockwise.
            2.  Install the batteries and close the battery compartment door. When replacing the GPS 
III+’s batteries, observe the polarity markings engraved in the plastic case.
            3.  Lock the door in the closed position by rotating the metal ring 90° clockwise.
Battery life varies due to a variety of factors, including temperature, use of 
an external antenna, and backlighting. You may find that the battery life varies 
in different conditions and that lithium batteries provide longer life in colder 
conditions. An internal 10-year lithium battery will retain your data while you’re 
changing batteries.
Polarity 
Markings
H 
						

							What is GPS?
GETTING STARTED
The Global Positioning System (GPS) is a system of 24 satellites which circle the 
earth  twice  a  day  in  a  very  precise  orbit  and  transmit  information  to  earth.  The  GPS 
III+ must continuously “see” at least three of these satellites to calculate your position 
and track your movement. At times, additional satellites may be needed to determine 
a position. Visit the GARMIN web site for more information on GPS.
By  using  an  almanac  (a  timetable  of  satellite  numbers  and  their  orbits)  stored  in 
the  receiver’s  memory,  the  GPS  III+  can  determine  the  distance  and  position  of  any 
GPS satellite and use this information to compute your position.
Your  GPS  receiver  can  only  see  satellites  above  the  horizon,  so  it  needs  to  know 
what satellites to look for at any given time. To use this almanac data, your GPS needs 
to  either  be  told  its  general  location  (“initialized”)  or  given  the  opportunity  to  find 
itself. Once you initialize the unit to a position, it will typically compute a fix 
within a 
few minutes. We’ll show you how to initialize your new GPS III+ on page 5.
Initialization is only necessary under the following conditions:
• The first time you use your receiver (new from the factory).
•  After the receiver has been moved over 500 miles (with the power off) 
from the last time you used it.
•  If the receiver’s memory has been cleared and all internally stored data 
has been lost.
Because  the  GPS  III+  relies  on  satellite  signals  to  provide  you  with  navigation 
guidance,  the  receiver  needs  to  have  an  unobstructed,  clear  view  of  the  sky  for  best 
performance. In a nutshell, the GPS receiver’s view of the sky will generally determine 
how  fast  you  get  a  position  fix —or  if  you  get  a  fix  at  all.  GPS  signals  are  relatively 
weak  and  do  not  travel  through  rocks,  buildings,  people,  or  metal,  so  remember  to 
keep a clear view of the sky at all times for best performance.
Hold the receiver at a 
comfortable height with the 
antenna pointing up.
When new (or if a position 
cannot be determined after 
10 minutes), the GPS III+ 
will prompt you to initialize 
the receiver. The unit needs a 
starting position to determine 
which satellites are in view.
4 
						

							Once the GPS III+ has calculated a position fix, you’ll usually have anywhere from 
five  to  twelve  satellites  in  view.  The  receiver  will  then  continuously  select  the  best 
satellites  in  view  to  update  your  position.  If  some  of  the  satellites  in  view  get  blocked 
or  “shaded,”  the  receiver  can  simply  use  an  alternate  satellite  to  maintain  the  position 
fix.  Although  a  GPS  receiver  needs  four  satellites  to  provide  a  three-dimensional 
(3D)  fix,  it  can  maintain  a  two-dimensional  (2D)  fix  with  only  three  satellites.  A 
three-dimensional fix means the unit knows its latitude, longitude, and altitude, while 
a two-dimensional fix means the unit knows only its latitude and longitude.
Initializing Your GPS III+
To initialize the GPS III+, take the receiver outside and find an open area where the 
antenna  has  a  clear  view  of  the  sky.  You  may  either  hold  the  receiver  at  a  comfortable 
height  with  the  antenna  pointing  up  (see  page  4),  or  mount  the  receiver  on  the  dash 
of  a  vehicle  (Appendix  A)  or  on  a  bike.  (Likewise,  when  you  use  your  GPS  III+  in  a 
vehicle, make sure the antenna is pointing up.)
To turn the GPS III+ on, press and hold the red power key.
The  Welcome  Page  will  be  displayed  while  the  unit  conducts  a  self  test.  Once
testing is complete, the Welcome Page will be replaced by a warning page, then by the 
Satellite  Status  Page.  A  message  will  inform  you  to  “select  initialization  method”.  (If 
the  initialization  prompt  has  not  automatically  appeared,  press  MENU  and  highlight 
‘Initialize Position’ and press ENTER.)
To initialize your unit:
           1.   Press ENTER to acknowledge the message and see a list of initialization options.
           2.  Use the rocker keypad to highlight ‘Use Map’, and press ENTER.
           3.  Use the rocker keypad to point the map cursor to your approximate location (within 250 
miles). You may also wish to use the IN and OUT zoom keys to make it easier to identify 
your approximate position.
           4.  Press ENTER to select the position and begin searching for satellites.
Check the Satellite Status 
Page for ‘2D Navigation’ or 
‘3D Navigation’ to verify a 
position fix.
To initialize the GPS III+, 
designate your approximate 
location directly on the map 
display. Use the rocker keypad 
and IN/OUT zoom keys to 
position the cursor on the 
map.
5
GETTING STARTED
Initialization 
						

							This usually provides a position fix in 1 minute. You’ll know you have a fix when 
the  unit  automatically  transitions  from  the  Satellite  Page  to  the  Map  Page,  unless  you 
have manually changed pages (shown left). Your receiver is now ready to use!
To turn the unit off:
           1.  Press and hold the red power key for 1 second. 
Troubleshooting
If you have trouble initializing or getting a position fix, check the following:
•  Does the receiver have a clear view of the sky?
  If there are large buildings or mountains, or if there is heavy tree cover, the receiver 
may not be receiving enough satellite signals to calculate a fix. Also, if you’re using 
the GPS III+ on a car dash, make sure the unit is placed so that it has the clearest 
possible  view  of  the  sky.  Your  GPS  will  only  be  able  to  detect  satellites  that  it  can 
“see”  through  your  vehicle’s  windshield.  Depending  on  the  slope  of  your  dash  or 
the  overall  surface  area  of  the  window,  it  may  be  necessary  to  mount  an  external 
antenna on your vehicle’s roof or trunk in order to give the unit a better view of the 
sky.  (Contact  your  local  GARMIN  dealer  or  GARMIN  Sales  and  inquire  about  the 
GA 26C low-profile remote antenna, part number 010-10052-04.)
•  Have you selected the right area when initializing?
  Check  for  the  correct  approximate  position  on  the  Map  Page  (press  PAGE 
until  the  Map  Page  appears;  see  pages  7  and  10),  or  reselect  your  approximate 
location to restart the initialization.
•   Have  you  moved  more  than  500  miles  from  the  last  calculated  position 
with the receiver off?
  Reinitialize  the  receiver  by  selecting  your  approximate  position  on  the  map,  or 
select ‘AutoLocate’ from the Satellite Status Page options (see page 29).
Once the GPS III+ has a posi-
tion fix, it will automatically 
transition from the Satellite 
Status Page to the Map Page.
If powering the III+ with 
external power, and the exter-
nal power is lost, the unit will 
automatically turn off after 30 
seconds.
6
GETTING STARTED
Initialization 
						

							To turn the GPS III+ back on, press and hold the red power key.
The GPS III+ features six main pages which are linked together in a chain. You can 
quickly scroll through the pages in either direction using the PAGE or QUIT keys. Let’s 
briefly  tour  each  of  these  pages  in  order  to  give  you  some  insight  into  how  they  help 
you navigate. We’ll go over all of them in more detail in the reference section.
Press the PAGE key to move 
through each of the main 
pages in normal fashion.
Press the QUIT key to 
sequence through the main 
pages in reverse order.
7
GETTING STARTED
Main Page Sequence
Compass PageHighway Page
Map PageActive Route Page
Position PageSatellite Status Page 
						

							Let’s  start  with  the  Satellite  Status  Page,  which  is  the  page  you’ll  view  while 
your unit is getting a position fix. If you’re not already on this page, press PAGE or 
QUIT  until  it  appears.  The  Satellite  Status  Page  shows  you  status  information  that 
helps  you  understand  what  the  receiver  is  doing  at  any  given  time,  and  it’s  a  page 
that you’ll want to occasionally refer back to as you use your unit. It features a sky 
view  of  available  satellites,  corresponding  signal  strength  bars,  the  status  of  your 
current  position  fix  (acquiring,  2D,  3D,  etc.),  and  your  estimated  position  error 
(EPE).  You  can  also  tell  how  much  battery  power  is  remaining,  and  you  can  adjust 
the screen contrast/backlighting by pressing the rocker keypad.
Satellites  are  indicated  on  the  sky  view  and  the  signal  strength  bars  by  their 
corresponding number, from 01 through 32. The sky view shows where it is looking 
in  the  sky  for  each  satellite,  by  indicating  the  direction  and  elevation  (angle  above 
the horizon). The signal strength bars depict the relative strength of the signal from 
each satellite being received. The taller the bar, the stronger the signal.
The  signal  strength  bars  give 
you an indication of what sat-
ellites are visible to the receiv-
er, whether or not they’re being 
used to calculate a position fix, 
and the signal quality.
If satellite reception is lost, 
or an insufficient number of 
satellites are available, you 
will be alerted with a ‘Poor 
Coverage’ receiver status and 
message.
8
GETTING STARTED
Satellite Status Page
Satellite Status Page
Receiver Status
Battery Level 
Indicator
Signal Strength Bar
Sky View 
						

							The  Position  Page  shows  you  where  you  are,  what  direction  you’re  heading,  and 
how  fast  you’re  going—and  it’s  the  page  you’ll  want  to  use  when  you  don’t  have  a 
destination selected.
A  graphic  compass  display  at  the  top  of  the  page  shows  your  direction  of  travel 
(track)  while  you’re  moving,  while  six  user-selectable  data  fields  below  display  your 
current  speed,  average  speed,  trip  odometer,  trip  timer,  and  sunrise/sunset  times  at 
your  current  position.  “User-selectable”  means  you  can  change  them  to  display  other 
information. We’ll cover these fields more in the reference section.
Below  the  user-selectable  data  fields  are  additional  data  fields  to  display  your 
current  position,  along  with  current  time  and  date.  The  current  position  readout  can 
be  in  latitude/longitude,  UTM/UPS,  Loran  TD,  MGRS,  Maidenhead  or  one  of  several 
regional  grids.  Current  time  and  date  can  be  in  local  time  or  UTC  (Coordinated 
Universal Time).
Position Page showing UTM 
coordinates for use with 
USGS topographic maps, etc.
The trip odometer, trip timer 
and average speed readings 
can all be reset from the ‘Trip 
Computer’ option on the Main 
Menu. See page 74.
9
GETTING STARTED
Position Page
Position Page
Track CompassTrip Odometer
Current Time 
and DateCurrent Position 
Coordinates 
						

							The  Map  Page  shows  your  movement  using  a  real-time  track  log  (an  electronic 
breadcrumb  trail  that  appears  directly  on  the  map  as  you’re  traveling),  and  your 
present  position  as  a  pointer  icon  in  the  center  of  the  map.  The  Map  Page  also 
shows  any  nearby  lakes,  rivers,  highways  and  towns.    Use  the  zoom  keys  (IN  and 
OUT) to adjust the map to the desired scale.
To change the map scale:
           1. Press the IN zoom key to select a smaller scale and more detail for a smaller area.
           2. Press the OUT zoom key to select a larger scale and display a larger area.
The  map  can  be  oriented  with  the  top  of  the  page  always  pointing  north, 
oriented  along  your  desired  course,  or  it  can  automatically  rotate  to  keep  your 
current  direction  of  travel  (track)  at  the  top  of  the  screen.    The  default  setting  is 
‘North Up’, which keeps the top of the page always pointing north.
Nearby  waypoints  are  depicted  on  the  map  with  any  one  of  over  70  different 
symbols,  with  the  waypoint  name  shown  directly  above  the  symbol.  We’ll  cover 
more  about  the  GPS  III+’s  waypoint  features  and  the  Map  Page  in  the  reference 
section of this manual.
With the map oriented to 
‘track up’, the pointer always 
points up and the map rotates 
to your current direction of 
travel (track). Note the north 
indicator on the map.
You can also select a full-
screen map from the Map 
Page Options. See page 37.
10
GETTING STARTED
Map Page
Map Page
Present Position
Data Fields
Nearby Waypoint