Hi all I'm new here. I have a 98 dodge ram 3500 v10 with the infinity stereo in it I hooked up a new deck with a sub and amp and got everything working then I came to realize the front speakers will only work when on the radio not for cd, aid, USB or n e thing other than radio. Any ideas as to what my poblem is? Thanks ben

 

welcome to df.
my guess would be that your amp is powered from the "power antenna" wire, which is only putting out 12v when the radio is on.

check this with a voltage tester, and then power the amp with a different lead.

 

Do you not hear anything from the front speakers?

The front infinity speaker system consists of two speakers in each door that are bi-amped. The smaller speaker is a tweeter and takes the signal directly from the head unit as is, and the larger speaker has a built-in amp for mids/lows. The larger speaker's amp is turned on by a signal from the head unit which is typically driven by the power antenna lead on after market head units.

You should hear the tweeters in the front even if the larger speaker amp isn't on (at least that's the way it works in my 97 truck). Assuming your radio uses the power antenna trigger to turn on the speaker amp try disconnecting it and listen to the radio and see if you hear anything from the fronts. If you hear just the tweeters then the power antenna trigger isn't the problem, but if you lose the front speakers entirely then do as dhvaughan suggested and find another trigger to activate the speaker amps.

Some head units have separate wires to activate a power antenna and an external amplifier. Use the external amplifier trigger if you have one, or you can always tap into the switched power wire powering your radio (or any other switched 12v wire).

 

seriously, WTF??? This just wasted me several hundred dollars.

I thought my head unit was bad, so I went and bought a new one only to find it has the same damn problem.

finally I searched these forums (seriously, does it logically make sense that the front speakers wouldnt work with a head unit????

But I do have a quick question. If it uses the power from the output to power the amplified speakers, then the amp trigger won't provide enough power, right?

so instead it needs to be spliced into the Red wire? (If I remember correctly, Yellow is constant on, red is for when the stereos on only?)

Thanks!

 

I would say that in most cars these days the audio system is not a standalone item where HU plug-n-play is straightforward. I know from personal experience that GM integrates Navstar into theirs, and Acura requires a separate trigger to turn on the sub in my wife's TL.

To answer your question, the HU is not actually powering the infinity amplifier it's just sending a trigger to turn it on. You should be able to use the red (switched power) wire to trigger the speaker amp if your antenna trigger doesn't provide enough current to do the job (or shuts off when not in tuner mode).