Installing aftermarket radio

**vaindil** · 06-09-2014

This is for a 2004 Grand Prix without OnStar or Monsoon.

The display on my factory stereo is shot (everything on it lights up all the time, so it's impossible to tell what time it is or what station is on or anything else). I'm therefore trying to install an aftermarket radio, but I have no idea what to do. I got the dash off and the stock radio disconnected, but my radio just has a bunch of wires coming out of it and I don't know how to connect them or what I'm supposed to do with them. I've read on other places that I can lose key chimes and whatnot by installing an aftermarket stereo, and I'd like to keep that functionality if possible.

Any thoughts on how I'm supposed to be doing this?

**theaceofspades** · 06-09-2014

There are two harnesses you need. Go on crutchfield.com find what fits in your car then go on other websites and find it cheaper.

**vaindil** · 06-09-2014

crutchfield.com has no vehicle-specific wiring harnesses for an '04 Grand Prix. I'll keep looking....

**REDCRAPGP** · 06-09-2014

Gmos-04

**vaindil** · 06-10-2014

Dang, I didn't want to have to spend even more money on this. :/ Would GMOS-01 work? It's $20 cheaper and Amazon says it fits my car.

**REDCRAPGP** · 06-10-2014

Sure it'll fit

If you plan on not using the monsoon system amp and running separate speaker wires to a separate amp.

Stop being cheap and buy the correct harness or stick with the stock headunit

**burgundybullet** · 06-10-2014

He says in the first post that his car isnt equipped with the monsoon system.

**REDCRAPGP** · 06-10-2014

Damn I totally overlooked that ****..yea dont get the GMOS-04

**vaindil** · 06-13-2014

Alright, I'm wiring everything up now. My radio has a blue wire labeled "AUTO ANTENNA B(+)". There's no spot on the GMOS-04 for that wire. Where does it go?

EDIT: All wires are connected and crimped properly, I've verified that (RCA connections from my radio are connected to nothing). The radio functions, but I get no sound from my speakers whatsoever. Also, the memory isn't working on the radio as the station resets itself every time the car is restarted. *sigh* I'm probably going to have to bring this to a professional....

**simbah** · 06-13-2014

with the GMOS-04 the RCA connectors on your headunit should be connected with the RCA connectors on the GMOS-04. White RCA-left front, gray RCA-front right, green RCA -left rear, and purple RCA - right rear, brown wire to mute wire on HU, green wire to parking brake wireof HU, blue/pink wire to speed sense wire of HU, green/purple wire to reverse wire of HU, blue/white wire to radio amp turn on wire, red to radios ignition wire, all these connection should be on the 14 pin connector of GMOS-04

**vaindil** · 06-16-2014

I've got all the wires connected properly. The head unit powers up and is getting a radio signal, but I get no audio whatsoever. The chimes work, but they're so quiet as to be useless (yes, turned them up all the way with the little screw on the electronics box). Everything is connected properly, no sound. I'm giving up and will be returning everything in the next few days unless anyone has any advice as to what I could be missing.

**simbah** · 06-17-2014

If you do NOT have Monsoon then you do NOT need GMOS-04. What you need is the GMOS-01. Then you will have sound, provided everything is connected properly.I didn't see first post properly til now.....Sorry

**wyoprix** · 06-17-2014

my car doesnt have monsoon or onstar either go buy the cheap one at autozone like 21 dollars i bought the expensive one online with the door dinger an **** 65? dont do it it ****s with your car get the cheap simple one it works great hooked it up with a steering wheel control interface works great just make sure u disconnect your battery for afor awhile an if it acts funny disconect for a bit longer an run a seperate power line to the assesory fuse on the passenger side

**wyoprix** · 06-17-2014

if u get a dvd player get a brake bypass so u can watch videos while driving some dvd players wont let u watch while driving it took me a week to get my system setup after fixing all the small bs glitches i encounteed on the way,, for some dumb reason GM decided to tie the radio into the cars computer an if u dont get it right it ****s with the ecm an gauges an **** go wack an u can blow your motor

**vaindil** · 06-17-2014

Originally Posted by simbah

If you do NOT have Monsoon then you do NOT need GMOS-04. What you need is the GMOS-01. Then you will have sound, provided everything is connected properly.I didn't see first post properly til now.....Sorry

So the GMOS-04 won't work? I need to return the GMOS-04 and get the GMOS-01? I thought the GMOS-04 would still work, which is why I kept it.

Originally Posted by wyoprix

my car doesnt have monsoon or onstar either go buy the cheap one at autozone like 21 dollars i bought the expensive one online with the door dinger an **** 65? dont do it it ****s with your car get the cheap simple one it works great hooked it up with a steering wheel control interface works great just make sure u disconnect your battery for afor awhile an if it acts funny disconect for a bit longer an run a seperate power line to the assesory fuse on the passenger side

I want to keep the door chimes, however. I don't have a steering wheel control interface either and I don't need one; I just need to replace the head unit.

**vaindil** · 07-07-2014

The GMOS-01 did the trick and fixed the problem. Of course, as soon as I get it in and working the volume knob on my radio stops functioning, so I had to switch back to stock for the time being. Oh well, such is life. Thanks everyone for all of your help!

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