Just wondering if the blue antenna wire used to power the antenna is 12v live? If not, does it get the power from the head unit?

I'm trying to diagnose a slow battery drain, and can't seem to figure out where it might be coming from; or if I even have a drain and the battery is just defective. I only noticed the battery dying after connecting the antenna power wire, and leaving the car sitting for 4 to 5 days.

My only mods involving anything electrical have been an installation of a JVC KD-NX5000 head unit. I used a wire harness from Crutchfield to aid in the install, and from what I can see, everything is connected properly.

 

Are you talking about the blue wire in the wire harness or the one coming from the headunit. Regardless, if you don't have any amps, the blue wire, and/or blue/white wire if your HU has it, should not be hooked up to anything. Just tape them off. The blue wire coming out of the harness should not be hooked up to anything either since our cars don't come with power antennas. It doesn't power the antenna itself, it powers the motor, or relay, to raise and lower then antenna on such equipped cars.

 

I originally did not have the blue wire coming out of the HU attached to the blue wire in the harness, but my FM/AM reception suffered. It was not until later that I realized that the antenna was actually amplified. So, I ended up connecting the blue wires together.

If they're not supposed to be connected, how does one compensate for the poor reception?

 

I've never heard of a factory amplified antenna, except maybe for those in-glass antennas. That doesn't mean that it's not though. I don't know. I don't have mine hooked up and I have good reception. Is there actually a wire coming out of the factory plug that coincides with the blue wire? Did you actually get better reception by hooking it up?

 

Yes, reception improved ten-fold by connecting my blue antenna wire from my HU to the blue power antenna wire on the harness. For example, I could not tune into any AM stations prior to connecting the wire. Now, I have reception to all AM stations in my area. FM reception has also improved greatly.

From what I've read on these forums, is that the antenna is amplified and will require a 12v source in order to operate correctly. I just don't know if connecting this wire is causing some sort of a slow drain on my battery; hence my question.

 

Why not just do a battery draw test to see what the problem is?

 

not to bump up old thread, but i did find that evo 9's antenna is indeed a powered one, at least for my JDM unit. the antenna cable is actually a pair of wires, one carrying the RF signal and another is for 12V input.

i played around connecting and disconnecting the 12v input while the radio is on. the improvement in terms of reception is noticeable.

 

Can confirm, Evo7 JDM, the antenna definitely needs power, or the AM doesn't work and FM is poor :P

The pioneer headunit I put in (DMH-Z5350BT) didn't have a blue wire (antenna remote) coming from its wiring harness (the old Sony unit I removed with USB did have the blue wire - along with an older CD player from my other car)

To power the antenna cable, I simply connected the car loom antenna remote power, onto the 12v ACC (red) coming out of the pioneer loom (so there's 2 wires connected to the red wire of the pioneer loom - the antenna and the 12v acc from the car).

I guess that just means, anytime the ACC is on, the antenna is powered... whereas if the headunit actually had the blue cable, power to the antenna would of been controlled by the headunit itself being turned on or turned off.

In the end, it really doesn't matter, it works