So, I got a Grom BT3 with the HD radio adapter. With the supplied antenna, I couldn't get reception worth a darn, so I bought the Metra adapters and a 17 foot extension cable. Hooked those up to the stock antenna, and split it to the Grom and the factory radio. Getting somewhat better reception, but not what it should be, and the stock radio is not getting the reception it was before. Not even close. What I have traced it down to I believe is the Metra adapter from the stock antenna. It's a two port connector that was plugged into the back of the stock tuner in the trunk. It has two leads going into it. However, the Metra adapter is only using one. I am pretty sure that it's using the wrong one. So, my question is, is their an adapter that uses both? Or, has anyone else come across this problem and found a fix? Any help is greatly appreciated. This is on an early 2001 ls430 with ML and nav.

Otherwise, the Grom is fantastic, and when I get reception, the HD radio sounds way better than regular FM.

Thanks!

 

Nobody else has run into this problem?

 

IIRC, the audio antennas are in the rear glass, and there are two.

 

So, after much trial and error, I think I got it figured out. I thought I would post my solution in case anyone having this problem in the future finds this thread.

I first tried removing the antenna adapter from the clip and temporarily installed it on the second lead from the antenna system. That worked better, but still wasn't what it was when stock. So, I ordered a second Metra adapter for the antenna side and took the lead I removed from the first adapter, and inserted it into the second slot of the new adapter. Then, I took a 2f/1m y adapter and combined the two antenna leads. Next, I took a 1f/2m y adapter and spilt them to the grom and the stock tuner. Now, I am getting great reception on the grom hd tuner, and the stock fm tuner. A lot of effort, just to get a good signal, but worth it in the end. Stereo sounds fantastic.