Chevy SSR Forum banner

Aftermarket radio install problems

10K views 6 replies 2 participants last post by  tshort 
#1 ·
I'm starting to really hate Bose.....

Anyways, over the last 2 days I've gone through the trouble of installing a single-din Pioneer head unit I had in my old truck. Pretty cool little unit...has XM/Sirius, iPod connection, bluetooth audio, HD, bluetooth phone, etc.

I used the GMOS-04 to connect to the stock Bose setup. So everything works but not very well. The volume is very low and when I try and crank it up the amp appears to start cutting out like it's too much load. I can select to use or not use the internal amp in the radio and neither selection has made a difference. I've gone through pretty much all the settings on the head unit but nothing seems to help the situation. I found some old threads that mentioned pulling the amp fuse, waiting a few seconds, then putting it back in. Tried that and it still didn't help.

I'm wondering if the GMOS-04 is to blame? It's like it's not feeding the amp the correct signal or bypassing it alltogether or something.

The stock radio worked just fine before this install and during the install I had the airbag, radio, and amp fuses pulled.
 
See less See more
#2 ·
Hmmmm

I just did some more searching on the google and found this:
Distorted Audio Output:
When using the GMOS-04 with a radio that has a high pre-out voltage,
usually greater than 2 volts, the audio signal may become distorted.
To resolve this follow these steps:
1. Make sure the ignition is turned to the “off” position
2. Disconnect the 10 pin and 16 pin wire harnesses from the GMOS-04
3. Open up the GMOS-04 by squeezing the sides of the top cover
4. Locate the potentiometer next to the 10 pin board mounted connector
located at the end of the GMOS-04
5. Taking a small flat headed screwdriver, turn the potentiometer counterclockwise
to lower the input level going to the factory amplifier
6. After adjustment replace top cover of GMOS-04 and reconnect wire
harnesses.

Maybe I should try that? I remember seeing a little adjustment slot and thought "hmmm, what's that for?" I sure hope I can get to the unit by just pulling out the head unit and not having to pull out that entire dash again. What a pain!

If anybody else has any other suggestions please fire away.
Thanks.
 
#3 · (Edited)
MAKE SURE you mark that pot in a manner that you can reset it if it does not work as you expect, and count the number of turns you make so you can get back where you started, or reasonably close. Good luck and besure to post your results.
 
#5 ·
Well, it was the little potentiometer on the GMOS-04 unit. Man, how goofy. It's much better now and I can get some volume now but the Bose amp seems to still want to cut out when you really crank it up. I'm not sure if that's the Bose to blame or the GMOS-04 but either way if you want some decent sound quality you pretty much have to go all aftermarket.
 
#6 ·
can you play the Bose amp against the potentiometer on the GMOS-04 unit to get it to max (a little more of one and less of the other until you find the optimum)?
 
#7 ·
Not sure what you mean exactly by playing with the Bose but basically the Bose amp doesn't like full power from my head unit. I tried playing with the amped or non-amped output of my head unit but it didn't seem to matter. So basically I tuned the potentiometer so that max volume was just a tad more than I'd ever listen to and now when I turn it up as loud as I want it the sound is smooth and clear.

I've got an old Precision Power amp that I plan on testing when I get a chance to see if it still works. If it does, I plan on using it to power a single shallow mount 10" sub that I'll put in a slim box just behind my seat.......at least that's the plans. I'll let you guys know how that works.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top