Except as expressly provided herein, no part of this manual may be reproduced, copied,
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the express prior written consent of Garmin. Garmin hereby grants permission to download a
single copy of this manual and of any revision to this manual onto a hard drive or other electronic
storage medium to be viewed and to print one copy of this manual or of any revision hereto,
provided that such electronic or printed copy of this manual or revision must contain the complete
text of this copyright notice and provided further that any unauthorized commercial distribution of
this manual or any revision hereto is strictly prohibited.
Garmin International, Inc.
1200 E. 151st Street
Olathe, KS 66062 USA
Telephone: 913.397.8200
Aviation Panel-Mount Technical Support Line (Toll Free) 1.888.606.5482
www.garmin.com
Garmin (Europe) Ltd.
Liberty House, Bulls Copse Road
Hounsdown Business Park
Southampton, SO40 9RB U.K.
+44/ (0) 870.8501241
Garmin AT, Inc.
2345 Turner Rd., SE
Salem, OR 97302 USA
Telephone: 503.581.8101
RECORD OF REVISIONS
RevisionRevision DateDescription
A06/09/08Initial Release
B01/18/11Clarified backlighting info
C04/13/11Clarified mono/stereo headset switch info
D06/16/12Corrected temperature range spec
GMA 240 Installation Manual190-00917-01
Page ARev. D
INFORMATION SUBJECT TO EXPORT CONTROL LAWS
This document may contain information which is subject to the Export Administration Regulations
("EAR") issued by the United States Department of Commerce (15 CFR, Chapter VII, Subchapter C) and
which may not be exported, released, or disclosed to foreign nationals inside or outside of the United States
without first obtaining an export license. The preceding statement is required to be included on any and all
reproductions in whole or in part of this manual.
WARNING
This product, its packaging, and its components contain chemicals known to the
State of California to cause cancer, birth defects, or reproductive harm. This
Notice is being provided in accordance with California's Proposition 65. If you
have any questions or would like additional information, please refer to our web
site at www.garmin.com/prop65
.
CURRENT REVISION DESCRIPTION
Revision
D
Page
Number
1-31.3.2Correct temp range spec
3-23.2
4-64.5.2Corrected description in Table 4-8
A-1, A-2Appdx AAdded connector numbers to drawings
Section
Number
Description of Change
Removed #16 AWG wiring info, updated Table 3-2
and wiring info
DOCUMENT PAGINATION
SectionPage Range
Table of Contents i – vi
Section 11-1 – 1-4
Section 22-1 – 2-6
Section 33-1 – 3-4
Section 44-1 – 4-10
Appendix AA-1 – A-3
Appendix BB-1 – B-4
Appendix CC-1
190-00917-01GMA 240 Installation Manual
Rev. DPage i
GMA 240 HARDWARE MOD LEVEL HISTORY
The following table identifies hardware modification (Mod) Levels for the GMA 240 Audio
Pan e l. Mod Levels are listed with the associated service bulletin number, service bulletin date, and the
purpose of the modification. The table is current at the time of publication of this manual (see date on front
cover) and is subject to change without notice. Authorized Garmin Sales and Service Centers are
encouraged to access the most up-to-date bulletin and advisory information on the Garmin Dealer
Resource web site at www.garmin.com using their Garmin-provided user name and password.
MOD
LEVEL
SERVICE
BULLETIN
NUMBER
SERVICE
BULLETIN
DATE
PURPOSE OF MODIFICATION
GMA 240 Installation Manual190-00917-01
Page iiRev. D
Aviation Limited Warranty
All Garmin avionics products are warranted to be free from defects in materials or workmanship for: one
years from the date of purchase for new Remote-Mount and Panel-Mount products; one year from the date
of purchase for new portable products and any purchased newly-overhauled products; six months for
newly-overhauled products exchanged through a Garmin Authorized Service Center; and 90 days for
factory repaired or newly-overhauled products exchanged at Garmin in lieu of repair. Within the applicable
period, Garmin will, at its sole option, repair or replace any components that fail in normal use. Such
repairs or replacement will be made at no charge to the customer for parts or labor, provided that the
customer shall be responsible for any transportation cost. This warranty does not apply to: (i) cosmetic
damage, such as scratches, nicks and dents; (ii) consumable parts, such as batteries, unless product damage
has occurred due to a defect in materials or workmanship; (iii) damage caused by accident, abuse, misuse,
water, flood, fire, or other acts of nature or external causes; (iv) damage caused by service performed by
anyone who is not an authorized service provider of Garmin; or (v) damage to a product that has been
modified or altered without the written permission of Garmin. In addition, Garmin reserves the right to
refuse warranty claims against products or services that are obtained and/or used in contravention of the
laws of any country.
THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF
ALL OTHER WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING ANY
LIABILITY ARISING UNDER ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE, STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YOU
SPECIFIC LEGAL RIGHTS, WHICH MAY VARY FROM STATE TO STATE.
IN NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE OR
INABILITY TO USE THE PRODUCT OR FROM DEFECTS IN THE PRODUCT. SOME STATES DO
NOT ALLOW THE EXCLUSION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE
ABOVE LIMITATIONS MAY NOT APPLY TO YOU.
Garmin retains the exclusive right to repair or replace (with a new or newly-overhauled replacement
product) the product or software or offer a full refund of the purchase price at its sole discretion. SUCH
REMEDY SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY FOR ANY BREACH OF
WARRANTY.
Online Auction Purchases: Products purchased through online auctions are not eligible for warranty
coverage. Online auction confirmations are not accepted for warranty verification. To obtain warranty
service, an original or copy of the sales receipt from the original retailer is required. Garmin will not
replace missing components from any package purchased through an online auction.
International Purchases: A separate warranty may be provided by international distributors for devices
purchased outside the United States depending on the country. If applicable, this warranty is provided by
the local in-country distributor and this distributor provides local service for your device. Distributor
warranties are only valid in the area of intended distribution. Devices purchased in the United States or
Canada must be returned to the Garmin service center in the United Kingdom, the United States, Canada,
or Taiwan for service.
Garmin International, Inc.Garmin (Europe) Ltd.
1200 East 151st StreetLiberty House, Bulls Copse Road
Olathe, Kansas 66062, U.S.A.Hounsdown Business Park
Phone:913/397.8200Romsey, SO40 9RB, U.K.
FAX:913/397.0836Phone:44/ (0) 870.8501241
FAX:44/ (0) 870.850125
190-00917-01GMA 240 Installation Manual
Rev. DPage iii
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GMA 240 Installation Manual190-00917-01
Page ivRev. D
TABLE OF CONTENTS
PAR AG RAPHPAGE
Section 1 GENERAL DESCRIPTION .............................................................1-1
Table 4-16 COM Swap ....................................................................................................... 4-10
190-00917-01GMA 240 Installation Manual
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GMA 240 Installation Manual190-00917-01
Page viiiRev. D
1 GENERAL DESCRIPTION
P ILO TCOPILOT
MUTE
MON
SQ
OFF/
VOL
SQ
VOL
PULL
MUSIC
VOL
TEL
GMA 240
PILOT
IS O
MUTE MUS IC
MUS IC
IC S
RADIO
NAV1NAV2AUX1AUX2
COM1
MIC
COM1
COM2
COM2
MIC
TEL
1
1-2
1
2
1.1 Introduction
This manual provides the installation instructions for the Garmin GMA 240 Audio Panel. Reference to
GMA 240 throughout this manual refers to all versions of the unit. Information pertaining to the
maintenance of the unit can be found in the GMA 240 Maintenance Manual, P/N 190-00917-02.
Information pertaining to the operation of the unit can be found in the GMA 240 Pilot's Guide, P/N
190-00917-00.
1.2 Equipment Description
The Garmin GMA 240 Audio Panel is not a TSO-certified product and has received no FAA approval or
endorsement.
The GMA 240 meets the needs of aircraft owners and operators who require reliability and versatility in
the essential audio switching function. LED-illuminated push-button simplicity and intuitive panel layout
allow audio selection of both NAV and COM audio. Large, single-button activation of the COM
microphone and audio for two COM transceivers simplifies cockpit workload. Photocell dimming
circuitry automatically adjusts the brightness of the annunciators to a level appropriate for ambient cockpit
light. The brightness of the backlighting is controlled by the aircraft lighting bus. A fail-safe circuit
connects the pilot's headset and microphone directly to COM1 and a fail-safe warning audio input in the
event that power is interrupted or the unit is turned off.
Additionally, the GMA 240 includes a four-position intercom (ICS) with electronic cabin noise deemphasis, two stereo music inputs, and independent pilot and copilot/passenger volume controls. To
further simplify the cockpit workload, the intercom provides for pilot isolation. One hundred percent solid
state circuitry and extensive use of surface mount technology are employed.