I am wondering if anyone else

[RJD]

connected their gps to the AUX circuit and been able to add another device at the same time. We are listening to these devices called walk abouts which basically are books on tape in one unit. when we plug one into the circuit, (I have split the circuit) with the gps connected, nothing works.

 

I thought others were also doing this. Was I wrong?

 

Bob

[slick97spirit]

If I try that I basically have to unplug the aux from the gps and plug it into the Ipod. I have the same music on both, so I don't do that anymore. Come to think of it, I think I can get recorded books on my gps mp3 player. hmmmmmm

[V7Goose]

You should NEVER connect more than one device at a time to those audio jacks unless you have a load isolation device on at least one of them! Headset and audio output jacks on portable devices are never designed to protect against cross-wire issues with other devices, so by plugging multiple devices into the same jack you can experience many problems, ranging from reduced volume, audio interference, burned out speakers (or preamps), and complete destruction of a connected device.

 

Here is a little background on why those bad things happen. Speakers require two wires to complete the audio circuit, and usually one of those wires is just a ground; this is especially common in vehicle radios. It makes no difference at all to the speaker OR to the device which wire is grounded (ignoring the phase issue for stereo), since a speaker is simply a completely isolated coil. But as soon as you connect another electronic device to the same jack, you create a different path back to ground. Even if both devices are wired identically, the impedance (load) on the audio output circuits of each device is massively changed, causing potential damage. That is why you almost always get a big drop in volume.

 

And if that second device has the audio output wires reversed internally, you have created a direct short of your audio out from device #1 to the negative power grid on device #2. This is never good, even if both devices are powered by their own batteries, but if both devices are actively powered by the vehicle's electrical system, that is where you can quickly destroy either or both of the connected devices. Sometimes is can be immediate, and some times they will seem to work until the overload causes damage somewhere down the road.

 

Goose