I installed a Sirius receiver (SIR-PAN1 receiver with a VaisTech interface) in my 04 LS and activated the account. All channels come in, all are displayed on my Nav screen, etc., and everything works BUT .....

Whenever I go under an overpass (even at 70+ mph) I lose signal for about a second when I'm about 200 ft. beyond the overpass. I also lose signal similarly when passing trees. It seems that my problem is antenna-related, as it happens in the very same locations each time I pass, and there are no other issues with the radio. My antenna is on the roof. I tried a new antenna, to have only the identical problem afterwards. My son has a Sportster in his car, and has no problems at all in the same areas, so the signal is good in those locations. He only has signal interruptions if STOPPED under an overpass.

Since I have tried everything (checked connections, new antenna, changing antenna locations on roof & trunk) I am wondering if the receiver requires a separate dedicated ground wire to its chassis/cover. I'm out of ideas at this point ..........

Sirius tech support is useless - instead of "thinking", they just read from a paper. I'm hoping someone may have experienced this problem and come up with a solution.

Thanks. Walt