problem with stereo

[Martin]

I just installed a stock radio, iSimple ISFM22 bluetooth FM modulator, and a RetroSound amplified hidden antennae.

http://www.amazon.com/iSimple-ISFM22-Universal-Bluetooth-Transmitter/dp/B0072L86GU/ref=sr_1_2/180-5453351-9998048?ie=UTF8&qid=1429406485&sr=8-2&keywords=isimple+bluetooth
http://www.crutchfield.com/S-llZ0l7aYaUq/p_068HPA1/RetroSound-HPA-1-antenna.html

It all works great when the key is in ACC position, but when I turn the key to ON (like when the motor is running) the radio stays on but I don't get any sound. WTF?

Any ideas what is wrong?

[kung fu jesus]

It may be that when you start the car, it cuts power to it, resetting it.

[Martin]

45 degrees with the top down this morning... I turned on the heater and the sound came on, too. LOL


Key in ACC position - radio works as it should
Key in ON position - radio display stays on, sound only works when the fan is on.

[tsingson]

Where did you tap your power and ground?

[Martin]

I used the OEM plug (lower-right of picture). Ground wire is attached from the screw in the red circle to the trans tunnel.


http://i1249.photobucket.com/albums/hh514/MartVerd/OEM%20Miata%20Radio%20Rear_zps0vgo5xh0.jpg (http://s1249.photobucket.com/user/MartVerd/media/OEM%20Miata%20Radio%20Rear_zps0vgo5xh0.jpg.html)

[tsingson]

Did you grab constant or ACC?

[Martin]

Also, there's smaller white plug behind the radio. I think it is the plug for the factory CD player (which I don't have), but I'm not sure about that. I tapped into a blue(?) wire on that plug to get switched power for the bluetooth module and the antennae. This is same wire that I used as the switch for the amp that I was using when I was using my phone/amp in a headunit-less system. So, that wire has power when the key is in ACC and ON.

[tsingson]

Try finding the constant 12V power for the radio and tap there. See if that helps. Did you use the switch that was included with the modulator?

[Martin]

I did not use the modulator switch. I have an app on my phone that can turn it off and on and change the FM frequency it uses. Pretty cool stuff.

What's really weird is that the radio's display stays on even when the sound isn't working. Does the radio have a different power source for the built-in amp?

[tsingson]

It's possible. I would try to go to the constant just to rule out power source as the problem.

[Martin]

Will do.

[tsingson]

Let us know what happens and then we can go from there. I am thinking that the power supply to the modulator is the problem.

[kung fu jesus]

I think Arkansas is the problem. :)

[Martin]

I unplugged this connector and all is well.

http://i1249.photobucket.com/albums/hh514/MartVerd/61546DE8-392B-4394-B665-1CC29C4AF6AC_zpsxzezwcux.jpg (http://s1249.photobucket.com/user/MartVerd/media/61546DE8-392B-4394-B665-1CC29C4AF6AC_zpsxzezwcux.jpg.html)

[tsingson]

I have no idea what that connector is.

[Martin]

I'm not 100% sure either. It has two wires that go to the plug in the back of the radio and the other wires go to the mass of wires that disappear up into the dash. I'm pretty sure my underdash wiring is the 93LE wiring so it's a little different than the 91 wiring. That plug probably is used with the MSSS stereo.