Help! No audio with new stereo
Thread Starter
Instructor
Joined: Apr 2012
Posts: 170
Likes: 1
From: Silicon Valley CA
Help! No audio with new stereo
I installed the Pioneer AppRadio 2 with GMOS-4. Everything seems fine for 5 seconds then the relay clicks and no more sound????? I've checked and rechecked. I switched relays. I even have video on the screen from my iPhone but no audio. If I press the ignition button the cycle starts over and I get sound for a few seconds but then the relay clicks and audio is gone again. I feel like something is wired backwards but I don't want to start experimenting and fry the whole system.
Any help is appreciated. I'd hate to go to the stereo shop tomorrow and beg for their help after I attempted this on my own
Any help is appreciated. I'd hate to go to the stereo shop tomorrow and beg for their help after I attempted this on my own
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
Are you sure you used the 'system remote' and not the 'antenna remote' for the trigger? If yes, it can still be fixed. If you're not sure try listening to FM, if sound returns then you used the wrong wire.
If you used the right wire, in addition to what you've already wired, connect a jumper wire from the HU blue/white system remote wire to the amp trigger terminal. If you're using oem amp/speakers then you need to connect the jumper to the wire on the car side of the gmos that is lined up with pin B3 of the big radio harness (wire on car side of plug will be white).
If you used the right wire, in addition to what you've already wired, connect a jumper wire from the HU blue/white system remote wire to the amp trigger terminal. If you're using oem amp/speakers then you need to connect the jumper to the wire on the car side of the gmos that is lined up with pin B3 of the big radio harness (wire on car side of plug will be white).
Thread Starter
Instructor
Joined: Apr 2012
Posts: 170
Likes: 1
From: Silicon Valley CA
I followed the instructions and I cut the blue/white wire between the 24 pin harness to the car and the 18 pin harness to the GMOS. Then I installed the relay with ground and 12v power. Tried the jumper, no luck. Connected the white wire (2 spaces over from the Red/white wire on the end) to the HU remote wire (blue/white). Same thing even on FM. Sound for a second then the relay clicks and nothing.
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
I'm with gerg, forget the relay 
On the gmos harness that connects to the car, about half way between the car plug and the gmos, cut the wire at B3 in half, tape the end going back to the gmos, connect the appradio blue/white system remote wire directly to the wire that goes to B3. That will power up your amp when the appradio is on.
You can take the relay out (my choice) or leave it there, shouldn't matter.
On the gmos harness that connects to the car, about half way between the car plug and the gmos, cut the wire at B3 in half, tape the end going back to the gmos, connect the appradio blue/white system remote wire directly to the wire that goes to B3. That will power up your amp when the appradio is on.
You can take the relay out (my choice) or leave it there, shouldn't matter.
Instructor
Joined: May 2012
Posts: 148
Likes: 1
If the diagram tells you to use a relay then USE one (there are reasons for this).
The radio's amp turn on lead should stay live the whole time the radio is on, the turn-on current to a open relay should no sweat for this lead. If not, that output is damaged on your radio and you either need to get it repaired or replaced.
Me thinks the relay is or may have been wired wrong. If not, without proper troubleshooting I'd suspect a bad radio.
The radio's amp turn on lead should stay live the whole time the radio is on, the turn-on current to a open relay should no sweat for this lead. If not, that output is damaged on your radio and you either need to get it repaired or replaced.
Me thinks the relay is or may have been wired wrong. If not, without proper troubleshooting I'd suspect a bad radio.
Thread Starter
Instructor
Joined: Apr 2012
Posts: 170
Likes: 1
From: Silicon Valley CA
Thanks guys. It is working for now by dumping the relay and jumping the remote to the amp. I'm going to leave the dash bezel off for a day or two in case I need to get back in there and change some stuff around. I really would rather use the relay but until I figure out why it won't work, this is a good fix.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
The relay is there because the GMOS has issues. I have never seen or heard of an aftermarket HU that couldn't handle triggering an amp. Not using the relay is a non-issue as long as you bypass the gmos.
Glad you got it working, now button it all up and go for a nice long drive
Glad you got it working, now button it all up and go for a nice long drive
Thread Starter
Instructor
Joined: Apr 2012
Posts: 170
Likes: 1
From: Silicon Valley CA
Mark, I think I found the root of my problem, Why would the blue/white remote wire from the HU have constant power, even when the car is off with the door open? It was my understanding that the remote wire got power a few seconds after the HU, therefore tripping the switch. If it has constant power then the relay never resets. Correct?
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
The blue/white wire is turned on/off by the HU. If the HU has switched power applied and is turned on then the blue/white wire is hot. Even with switched power applied (controlled by gmos), if the HU is turned off the blue/white wire should be off.
Even if it was on all the time (which would eventually kill your battery), then the relay should have just stayed pulled in all the time. The blue/white equivalent output from the gmos can't handle any current flow or it tripps off, so it's supposed to be wired to the coil of the relay (blue/white to 85 or 86, other of those two to ground). Then connect 30 or 70 to B+, and other of those two to B3. B3 would then be triggered on by B+ when gmos version of blue/white was hot. A standard relay diagram is here if you need it.
If your radio is turning off when you turn off the car and open a door, then it should be working properly. I'd leave it alone.
I don't know what your original issue was, the 'on for a few seconds' is not a normal problem. My guess would be that your gmos may have more issues than most, assuming you had everything connected properly. But again, if everything is working properly, I'd leave it be.
Even if it was on all the time (which would eventually kill your battery), then the relay should have just stayed pulled in all the time. The blue/white equivalent output from the gmos can't handle any current flow or it tripps off, so it's supposed to be wired to the coil of the relay (blue/white to 85 or 86, other of those two to ground). Then connect 30 or 70 to B+, and other of those two to B3. B3 would then be triggered on by B+ when gmos version of blue/white was hot. A standard relay diagram is here if you need it.
If your radio is turning off when you turn off the car and open a door, then it should be working properly. I'd leave it alone.
I don't know what your original issue was, the 'on for a few seconds' is not a normal problem. My guess would be that your gmos may have more issues than most, assuming you had everything connected properly. But again, if everything is working properly, I'd leave it be.