Daohaus

I have a dashcam that has a separate attachment for a rear camera that I have mounted at the top center of my rear glass. When I did my routing of this cable, I ran it across from the right side of the mirror and along the driver's side door seal and back to the camera.

Well I noticed that my GPS was acting all weird. Compass heading was totally off e.g. heading East but compass showing I was heading South. When I went to map mode on the PCM it was even more bizarre showing me cutting a swath across land and streets.

On a hunch, I thought I would disconnect the cable for the rear camera and within a second or 2 GPS corrected itself.

So it looks like I'll be re-routing that cable to go along the passenger side this weekend.

So dont be like me and run anything that has power/signal across where the mirror is mounted, your radio signal will degrade and so will your GPS.

StormRune

Just in case it helps you understand the location to avoid, here is a diagram showing the location of the GPS antenna in a 991. In the diagram, #1 is the GPS antenna, #2 is a radio antenna, and #3 is the GPS antenna cover (shield I assume).

Porsche_nuts

I have both front and rear dashcams. I run the wiring for the front camera along the passenger side headliner and the wiring for the rear camera along the driver side headliner. I've had no issue with my GPS or weirdness with maps.

Code

Good to know!

Daohaus

This is perfect thanks for the pic!

that's interesting, I'm not sure if it's acted weird all this time or I just took the time to notice compass lately but that's definitely the cause in my case.