higsplef

I have what appears to be 2 antenna wires that plus into my factory HU. One looks like the standard antenna connection, what is the 2nd smaller wire used for?

PuReChaos

Just a guess, but it could possibly be a ground wire.

Power6

This car has a "diversity antenna" system which is pretty common with OEM window antennas, there are 2 antennas, both in the rear window on the ES300 I believe. There reception advantages to the two antennas, the diversity tuner system somehow compares the two signals and makes one stronger signal out of it for FM radio.

For an aftermarket radio most don't support diversity, you can just plug the main antenna plug into the radio and leave the other one unplugged.

higsplef

Thanks that makes sense.. Appreciate the information

PFB

I don't have that model year, and I assume that its a power Antenna, so are you sure that that extra wire is not for raising or lowering the Antenna when the radio turns on or off?

davensd

The 1999 ES 300 has an integrated antenna in the rear window. So no antenna assembly to raise or lower.

davensd

PFB

You're right. I misread the year of his car. Thanks for pointing this out.

Phil

higsplef

All thanks again, yes it is a diversity antenna connection, the 1999 ES300 does not have an external antenna.