gps not working

katthater · #1 (**permalink**) 06-16-2009

trying to wire up my gps,
will work off the boat but not on the boat?
i am stumped.
red wire to 12 volt supply....
black wire to ground correct?
why will it not work? any ideas?

patrickrea · #2 (**permalink**) 06-17-2009

Breaker switched on? Blown fuse? could be almost anything.

sailingdog · #3 (**permalink**) 06-17-2009

It would help if you said what GPS unit and what boat you had, as well as how the GPS is wired on the boat. Posting a wiring diagram wouldn't hurt either.

roline · #4 (**permalink**) 06-17-2009

I have 2 mounted with boat power, Raymarine 630 and a Garman 45xl. I installed an external antenna for the 45 which helped to improve the accuracy. I used a light bulb with leads and a diode to verify power prior to hooking up. The diode only conducts in one direction which verified that the white was hot and black was the ground. One could assume red to be 12 and black ground, but it could have been wired incorrectly. Need to confirm continuity and polarity with a volt meter or with a simple rig like I made.