I keep on blowing a fuse and frying my gps

[ggreen]

Every time I plug my gps adapter into the cigarete lighter on my boat I blow a fuse in my gps. The fuse is located in the adapter. It fried my second gps. Luckly the dealer replaced both. I don't feel three times lucky, so I need help.<br />The cigarete lighter is attached to a 12v starting battery (no fuse in between) The cigarete lighter is a outdoor design. I did get a little corrosion on the terminal inside.

 

[islandboat]

Re: I keep on blowing a fuse and frying my gps

Use a test light and ground one end to a good ground on the vehicle. Touch the center of the power outlet and it should light up. That is wired correctly. If you touch the outter ring of the power port and it lights up, it is wired backwards. It can work for some items like that but not a gps.

 

[waterone1@aol.com]

Re: I keep on blowing a fuse and frying my gps

I agree with trophy, sounds like the polarity of the power outlet might be reversed. By the way, is the adapter cord the original one that came with the GPS, or is it an aftermarket ? Have you tried the GPS and adapter in your car?

 

[Xcusme]

Re: I keep on blowing a fuse and frying my gps

It wouldn't be a bad idea to put an in-line fuse on the lighter plug too. A dead short on that plug , will turn the wires red hot, possibly causing more grief, or worse a fire. The lighter is a resistive load and voltage polarity is not an issue. Any other use of the plug , as you already know, is polarity sensitive.

 

[18rabbit]

Re: I keep on blowing a fuse and frying my gps

When you are probing the receptacle, be very careful the conductive part of the probe does not touch the side and the center contact at the same time. This will create a direct short and you are not fused! You can also follow the ground wire from the receptacle to see if it really goes to ground or if it is connected to a power source somewhere. As Trophy175 mentioned, the (+) should be in the center and the (-) is on the side.<br /><br />I’m thinking I agree with Xcusme; there is no “maybe” about installing a fuse on that receptacle. It is something that must be done and should be put at the top of your ‘things to do’ list.

 

[ggreen]

Re: I keep on blowing a fuse and frying my gps

Thanks everyone for responding. I will be installing a fuse and checking my wires. What size of fuse should I use?

 

[18rabbit]

Re: I keep on blowing a fuse and frying my gps

GGreen - it kinda depends on where you put it. If located near the power source, normally the fuse would be sized to protect the wiring. If located near the terminal, it is commonly used to protect the accessory, which in your case is the receptacle itself. You should check with the manf of the recp to see what they rate it at (often 15-amps, sometimes 10-amps), then verify you have the appropriate wire size for that current/load, then install the fuse in the (+) wire near the battery or power distribution point.

 

[CTD]

Re: I keep on blowing a fuse and frying my gps

Check your adaptor too, I bought one from radio shack once that was wired backwards and it fried my cb the minute I turned it on. Radio shack bought it and a new cb for me but still a pita.

 

[ggreen]

Re: I keep on blowing a fuse and frying my gps

Thanks again everyone for responding. Today I changed the poitive and neg wireing around on my battery posts, and guess what the fuse never blow! I also installed a 10 amp fuse by the positive terminal. I bought this boat second hand and assumed that the wiring was correct. I have learned to never assume.

 

[18rabbit]

Re: I keep on blowing a fuse and frying my gps

Your getting closer but you might not be out of the water yet, unless you either (A) tested for the positive in the center of the receptacle or (B) you traced the wires back to their pos and gnd so know they are installed correctly. Btw, the fuse won’t blow unless you exceed the 10-amp rating. Fuses don’t care which way the current is flowing.

 

[springhead]

Re: I keep on blowing a fuse and frying my gps

to be on the safe side, make sure the 10 amp inline fuse u installed is smaller than the fuse in the gps,

 

[FreeBeeTony]

Re: I keep on blowing a fuse and frying my gps

I doubt very much that the GPS is drawing 10 amps. It's probably less than 2 amps. And if you changed the entire polarity of the battery........I would wonder what else got damaged?

 

[18rabbit]

Re: I keep on blowing a fuse and frying my gps

Originally posted by springhead:<br /> to be on the safe side, make sure the 10 amp inline fuse u installed is smaller than the fuse in the gps,

The 10-amp fuse is NOT providing protection for any accessory that gets plugged in. It is protecting the wiring up to and including the receptacle. Anything that gets plugged into the receptacle needs its own fuse/protection.<br /><br />Normally, protection for the accessory should be right at the accessory. Protection for the wiring is just the opposite; preferably within 12 or 18-inches of the power source (battery).

 

[waterone1@aol.com]

Re: I keep on blowing a fuse and frying my gps

GGreen, When you said that you "reversed the wiring at the battery" I am hoping that you found that the acessory plug had it's own wiring running back to the battery and that is what you reversed. If that wiring is not marked as to possitive and negative, please get some red electric tape from the hardware store and wrap an inch or two of the positive wire. That way you or anyone you sell the boat to will know what goes where the next time it's disconnected.

 

[TwoBallScrewBall]

Re: I keep on blowing a fuse and frying my gps

If he reversed everything the boat would be smoking already....