Installing Auxiliary Audio Device into the Monsoon Sound System


If you have a Monsoon Head Unit with an external CD changer connection port you may be able to install a device such as the GM9-AUX RCA converter.  With The GM9-AUX you can patch such things as a portable MP3 player or satellite radio system into the stock stereo of your GM vehicle.  There are differences in the Monsoon system depending on model year and type of Monsoon head unit.  Not all Monsoon decks support the CD changer port as required for the GM9-aux converter.  At the time of this writing a second device is also available that integrates with the Ipod and broadcasts on an unused FM frequency allowing you to ‘tune in’ the Ipod.


The GM9-AUX auxiliary plug converter can be found here.


Just plug an RCA to 1/8” stereo headphone jack adapter into the GM9-AUX converter and run it through/under/around the dash in a convenient location and plug the headphone end into whatever MP3 player you have. Voila!


The following are clippings from firebirdv6 message board (stereo/electronics) as well as a formal install guide I found on the web.


If you look real close at the picture, you can barely see the RCA's sticking out of the black box

The Modification Encyclopedia says:
Can I add a CD changer to my factory radio?
Yes, if you have a 98 or 99 than you must have the tape deck. You cannot add a CD changer to a CD Head unit in the 98-99 models. If you have a 2000-up then it doesn’t matter. You can add a changer to either the tape deck or CD player head unit."


For the heck of it though, pull the factory head unit out and see if the jack is even there. Here's a picture of what the jack will look like:


NOTE:  You may also be able to see the back of the radio by taking off the passenger side kneeboard and/or glove box shell in order to peek up near the radio with a flashlight.





The GM9-AUX will convert the 9-pin data port of any GM radio with CD changer controls to an auxiliary input. NOTE: For proper operation of the GM9-AUX, the factory CD changer, if present, will need to be disconnected from the factory harness.
· Not compatible with vehicles equipped with the 6-disc in-dash slave unit.
·  Not compatible with 96-99 am fm CD players with slave cassette unit.
· Radios from 2000 and before are not capable of controlling two units. Therefore, these vehicles will need to have the slave unit disconnected.
· Compatible with Pioneer Universal XM Satellite Digital Tuner System (GEX-FM903XM), when used with PIE Part# PIO/P-RCA.
· Compatible with Sony Universal XM Satellite Digital Tuner System (DRN-XM01R, DRN-XM01C), when used with PIE Part# 3.5-RCA6MM.


CAUTION: Before any connections are made, P.I.E. strongly recommends that all circuits be verified with a voltmeter before interfacing with them. P.I.E. also recommends that this Protocol Converter be installed by a Certified Car Audio Installation Technician. Always set the parking brake before working on any vehicle.


DO NOT force connectors together as pin damage may occur. This installation will be flawless if you take your time making the connections described below. Following the installation sequence below is critical to ensure proper recognition of the CD changer by the factory radio.




1. Disconnect the negative battery terminal.
2. Remove the factory radio to gain access to the connectors on back of radio.
3. Remove any connector that may be plugged into the 9-pin DATA port.
4. Plug the 9-Pin connector of the GM9-AUX into the mating socket on the back of the radio.
5. Plug the factory 9-pin DATA cable into the mating socket on the GM9-AUX. Factory CD changer, if present, will need to be disconnected from the harness.
6. Connect appropriate length patch cord (not included) between the GM9-AUX and auxiliary device.
7. Reinstall the factory radio.
8. Reconnect the negative battery terminal.




1. With radio on, activate auxiliary device.
2. Push the "TAPE/AUX"' TAPE/PLAY" button on radio to gain access to auxiliary audio input.
3. Display on radio will show CD 1 TRACK 1, and audio of auxiliary device will be heard.
4. Adjust volume levels of auxiliary device. (If applicable)