Originally Posted by Salsaman06

As a matter of fact I have. I owned a 2003 UL (bought new) and I installed an aftermarket XM radio *myself*. At the time, the only option was to use a XM radio that transmitted on a FM frequency in order to get it to play into the car's sound system. That method absolutely sucks if you rely on "over the air" transmission. So I decided to SPLICE into the antenna coax cable in order to connect the XM radio directly so that it transmitted directly into the tuner (thereby reducing/eliminating outside interference). I decided to splice as close to the tuner as possible. When I located the tuner (on the right side of the trunk down from the ML amp) imagine my surprise to find not one but two coax cables. I looked up what and where they go via the Lexus wiring diagrams I had for the LS at the time. And then I traced them to verify. So yes, I do know this aspect of the 2003 LS very well.

Now, I will not go so far as to say this applies to other model years. I can only vouch for the 2003 UL which is what I have experience with. But I would find it highly unlikely Lexus only did this in one model year - and even more unlikely they would put a Lexus Link-only antenna on *every* LS knowing it would only apply to less than 10% of the cars in any particular year. Also add to the fact that 2003 was the last year for Lexus Link because the cell carriers were moving to all digital and would be incompatible with current LL electronics. Given that fact, why on earth would they continue with this antenna on the '04,'05 &'06 if there weren't some other purpose to it?

Also, IIRC, there are actually 2 antennas inside that black thing on the roof - the one for the radio and the one for the cell phone. i.e. they do not share the same "antenna" but are co-located in the same housing. I may still have my wiring diagrams somewhere that showed that separation. If I do, I will post here.

Originally Posted by iToaster

It is apparent to me that you aren't as familiar with this aspect as you think. I have had all of the rear panels off when wiring in my JDM rear center arm rest (for its headphone jack), so I know what is back there. The wiring harness contains cables for both FM and cell systems in the same harness, but the one for the cell modem branches off where the Lexus Link ECU mounts and has nothing to do with the radio antenna. There are two cables at the tuner because of the diversity antenna system in the rear windshield (take the trim panels off and look for them if you don't believe me). For reassurance, there is no continuity on my multimeter between the roof mounted antenna base and either antenna input to the radio tuner. The antenna and base are listed under the telephone system in the parts catalog, and are listed all the way up to 2006. They are consistent between 2001 and 2003. The reason they hung around, I don't know, but I suspect that it's cheaper to only make one roof panel for the global market and the antenna be ornamental. There is not a second antenna in it, there is only one wire that comes out of it and it doesn't go to the radio tuner.

Originally Posted by Salsaman06

Well that's fine for your '01. As I said I wasn't going to speak for other models but mine. So we'll have to agree to disagree as they. I know what I saw on my '03 UL. If i can find my old pics I'll post.

Originally Posted by TTBomB

IToaster, any idea why my radio reception is awful after my roof antenna was removed?
I don't believe they would have disconnected the windshield one for no reason.
Thanks