GPS interferance to Joying Andoid Headunit

[Jamp]

Hi All,

After a fair bit of Youtube review viewing I opted for a Joying double-din headunit for my JDM Subaru Legacy. On the whole it seems a good unit, but it really struggles with GPS signal - often lurching along the road on the nav app (any app) and completely losing signal after 20 mins or so of driving. I'm in touch with Joying's tech support and they've suggested updating the firmware and trying a new GPS aerial, neither of which have helped. I've brought the headunit back into the house and powering from a 12v adapter, and it transpires that the GPS signal is much better - not just because my house doesn't move(!) but it clearly has a much better signal and gets it quickly. So I now suspect there's some interference in the car which effectively blocks the GPS signal to this unit (though not to my phone nor my GPS speedo). This applies even when the GPS aerial is outside of the car, so it's not a windscreen coating or similar. It also applies with the engine and ignition off (acc only).

Any bright ideas how I could suppress any noise which might interfere with the GPS, or what might be causing it?

[Sparky137]

Do you have a dash cam installed or any USB chargers? The power supplies on these can often emit a lot of electrical noise that effects GPS (and DAB) reception. If you do, try unplugging it/them and see if the reception improves.