Looks like you may need a new antenna module. If they don't give you a new one under warranty, are third party Garmin repair services that will fix it for cheap. Also, I found an DYI GPS repair guide,so you can do it yourself too, not that difficult. The part is on Ebay.
I found the source of interference with my Garmin 255W satellite reception. We were cruising in our old beater, a 1993 Oldsmobile Cutlass Ciera with the GPS in it's beanbag on the dash. This happens to put it directly above the factory Delco AM/FM/ Cassette unit. We have listened to AM radio kazillions of times with no GPS problem. Today we were listening to the iPod broadcasting into the FM tuner. All was well until I tuned to 87.7 MHz (a clean frequency which us THE last on the digital tuner). Shortly thereafter the GPS lost all satellites and navigation went to pot. After much confusion (swearing) and testing, I found the problem. Using the satellite reception screen I observed that all satellite activity diminished rapidly when tuned below 88.1 MHz. At 87.7 MHz all reception fell to zero. All FM frequencies over 88.1 MHz (and the entire AM band) caused no noticeable reception problem. There must be a harmonic frequency as part of the PLL circuit or some sympathetic from within the hysteresis system which causes this. Fascinating stuff!I found the source of interference with my Garmin 255W satellite reception. We were cruising in our old beater, a 1993 Oldsmobile Cutlass Ciera with the GPS in it's beanbag on the dash. This happens to put it directly above the factory Delco AM/FM/ Cassette unit. We have listened to AM radio kazillions of times with no GPS problem. Today we were listening to the iPod broadcasting into the FM tuner. All was well until I tuned to 87.7 MHz (a clean frequency which us THE last on the digital tuner). Shortly thereafter the GPS lost all satellites and navigation went to pot. After much confusion (swearing) and testing, I found the problem. Using the satellite reception screen I observed that all satellite activity diminished rapidly when tuned below 88.1 MHz. At 87.7 MHz all reception fell to zero. All FM frequencies over 88.1 MHz (and the entire AM band) caused no noticeable reception problem. There must be a harmonic frequency as part of the PLL circuit or some sympathetic from within the hysteresis system which causes this. Fascinating stuff!
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Looks like you may need a new antenna module. If they don't give you a new one under warranty, are third party Garmin repair services that will fix it for cheap. Also, I found an DYI GPS repair guide,so you can do it yourself too, not that difficult. The part is on Ebay.
I found the source of interference with my Garmin 255W satellite reception. We were cruising in our old beater, a 1993 Oldsmobile Cutlass Ciera with the GPS in it's beanbag on the dash. This happens to put it directly above the factory Delco AM/FM/ Cassette unit. We have listened to AM radio kazillions of times with no GPS problem. Today we were listening to the iPod broadcasting into the FM tuner. All was well until I tuned to 87.7 MHz (a clean frequency which us THE last on the digital tuner). Shortly thereafter the GPS lost all satellites and navigation went to pot. After much confusion (swearing) and testing, I found the problem. Using the satellite reception screen I observed that all satellite activity diminished rapidly when tuned below 88.1 MHz. At 87.7 MHz all reception fell to zero. All FM frequencies over 88.1 MHz (and the entire AM band) caused no noticeable reception problem. There must be a harmonic frequency as part of the PLL circuit or some sympathetic from within the hysteresis system which causes this. Fascinating stuff!