AM Radio Help

[Koz]

I recently added the OEM voice mic to my 05 nav (which works great). Since then I've lost AM reception (only AM). It sounds like the antenna is disconnected. Before taking it back apart and checking the antenna connection I was wondering if the AM and FM antennas are separate. Any info would be appreciated!

Koz

 

[Koz]

Just for info there are two antenna cables connected to the HU. One of them was off, when put back in the AM worked fine. The funny part is the FM worked fine when it was off . After I installed the one that was off I disconnected the other one and both the AM & FM worked. This does not make sense!

Koz

 

[greasefingers]

It is my understanding that the diversity antenna system works as follows: with two different types of antennas installed the HU will switch between them depending on which antenna provides the strongest signal. This is why an aftermarket HU cannot use this feature, even if some type of adaptor is used. The circuitry is missing for the switching part. So if I understand things correctly; the second antenna is not an AM

 

[Bobby]

Looks like the 2nd "diversity" antenna is FM only. The main antenna connection is FM and AM.

BTW - I have no idea how the main antenna plug came off while installing the mic for voice command. Luckily, it was an easy fix and all's well. The voice command is badass and anyone with a factory nav should get it.

 

[cknsls@adelphia]

This "diversity antenna" brings up an interesting point. So, for those of us that drilled and/or removed the plate for an '05 or '06 Scion head unit-does this radio even have the internal circuits for switching back and forth? If the second antenna plug is covered up-one would assume it does not. I am not going to lose sleep over this (I connected the second plug anyway) it's just would be interesting to know the answer!

 

[Bobby]

It's probably blocked b/c the Scions don't have a diversity antenna in their cars. Pioneer makes the stereos so they build it with the DA for other cars. It's cheaper to make one radio than 3 or 5.