scottf

I've seen a few posts about loss of radio reception here, but couldn't really find the cause of this.
I put in a new HU (JVC KD-SX980) last April. I put it in myself with the correct wiring harness. Everything worked just fine... CD's and radio sounded great. I had the same great reception that I had with with the stock HU. Then this past October (6 months later) the reception all of a sudden is gone. I can't get a thing AM or FM... even the local stations just up the road from me. I took it to a car audio place to double check my wiring and the found nothing wrong... told me that he thought the HU was back, so I swapped the stock HU back into the car and I still had no reception. I decided to take it to Honda. They replaced the antenna wire where it connected to the HU (that's all they told me they did) and I had reception again. I swapped my JVC HU back into the car it it worked great again. This morning the same thing happened... I started my car, and all of a sudden no reception AM or FM. I'm wondering what the problem might be. I'm guessing it's somewhere in the wiring of the JVC HU. I've read some things on here about the power antenna wire. I'm pretty sure that I got that connected correctly, but that's the only area that I can remember there being any doubt. Still, the stereo place didn't catch that. Also, would that cause this to happen? I've also read about the antenna amplifier located in the right C pillar. I've not looked in there (BTW how do I get in there?) but it seems weird that it would keep comming un hooked or loose in there. Does anyone have any idea what could be causing this. It is possible that I've got a bad HU, but it works just fine for the most part. How does it work fine for a few months and then just all of a sudden stop working? Any help would be appreciated.
Thanks!