How To: Easy GPS Hardwiring

What would happen if I didn't use a fuse...?

 

You wouldn't be protecting your expensive GPS unit from potential overload... for what would have costed a couple of bucks at most and a few minutes of time.

 

But doesn't the 12v power cord that connects to the GPS have a built in fuse in the plug part of it? How else would it be protected when plugged into a cigarette lighter?

 

It isn't paint, it is a custom dash cover that I ordered from a company out of California that does custom mats. It runs about 90 bucks but it fits like a glove and with the right amount of velcro it looks awesome. It keeps the temperature in the truck down to. I will post the website when I get back to Texas in another week, I have it written down.

 

If you hard-wire it, you're deleting that plug, and the fuse. Some units may have a fuse for ht incoming power in the unit, but I wouldn't place my money on it.

 

Miss understood your question. My dash was black from the factory, that is the color that of the radios in a 2007 regular cab.

 

Actually the hard wire has the exact same converter on it as the stock 12v has on it. The only difference other then the geometry of it is the 12v has it on the plug and the inline has it on a small block about half way up the cord. The 12v plug for the Garmin does not have a fuse in it. The only thing that you are loosing by using the hard wire is the radio traffic interface and it doesnt work everywhere anyway.

If you use the add a circuit like the op did and are worried about blowing something use a 7.5 fuse on it and you will be all right. The 12v plug on the dash has a 20 fuse on it so you are actually protecting it better.

 

You also run the risk of routinely overloading whatever circuit you tap the hardwire lead off of. That circuit is designed to have 8.5 amps run thru it (random number) and has a 10 amp fuse...but adding a whole nother section of wire with the GPS might make it draw 11amps...meaning you need to change out the fuse for that whole segment...

 

Something that you need to look at when you are using an add of circuit is what you are tapping into. I have a Base model so I dont have alot of the extras. This allows me to pick circuits that aren't used like 4wd or the power windows and power door locks. The additional circuit is just tied into the power source so there is no harm to the circuit that you are tying into.

 

Really in the end, I used the add-a-circuit because they are easy to use and I had the available open slot on the fuse panel that worked when I used the key. When using the add-a-circuit you MUST use a fuse or it will not work. The two metal prongs from the fuse make a complete circuit for the add-a-circuit. Hope that is what you were asking.

 

Thanks for the detailed write-up, layout and pictures! Pro-Installation for the do-It-Yourself Man! AAA+++ Thanks

 

thanks

 

Just did this. Worked great and super easy. I followed your directions to a T except I didn't have that ground bolt up top, (what option do you have mounted up there that I dont? I thought this thing was loaded..) anyway so i just grounded it down by the kick panel, and instead of using the 12v outlet, i just took the male plug apart and it has a hot and ground wire inside running to the electrodes. Ripped the connectors and springs and fuse out and just soldered the add a circuit to the hot/red wire and a scrap piece of wire to the ground/black wire and grounded it nearby. Works perfectly. Looks sooo much better. Thanks for taking the time for the how-to.

 

Excellent write-up ... many thanks!

 

I tried this, but when I turned the key, it blew the fuse in my GPS cord. Anyone have any idea what I did wrong to make the fuse blow?

 

Did you use this exactly like written? If you modified it, what did you change? The more info you give, the better I can help here.

I would start by checking to make sure that the voltage just before the plug to the GPS is within a 12v + or - 1 volt. Do you have anything else besides the GPS plugged into the add-a-circuit?

Like I said, the more info the better. Its hard to say right now what could have caused that. Could have been a one time overload to the GPS but Im not sure until I have more info.

 

I'm pretty sure I did everything exactly as you did, same fuse location and what not. Only real difference I can highlight is that I didn't get the exact same aux. power outlet, I got one from wal mart. How do I check the voltage? I pretty much suck with electrical work, which is why I'm not surprised I didn't get it right the first time.

 

You will need a volt meter to check the voltage. If you do not have a volt meter, you can get one for fairly cheap at HD, Lowes, Radio Shack, etc. You would use the volt meter on the hot wire at the point you connected up the aux power outlet. If you taped it or cover with shrink wrap, you will have to remove this first.

The other thing I would check is that both of the fuses in the add-a-circuit are inserted all the way and that the fuse total on the add-a-circuit is not more than the GPS is rated at. I am assuming that you know what the GPS's fuse is rated for because you said the fuse on the GPS cord blew.

Last thing I can think of to help would be to plug the GPS into the car cig lighter and see if it blows on factory plug to eliminate the factory cord for being the issue and not your install.

 

I'll check the voltage, am I gonna have to take the wire apart if I just used a crimp? The fuse for the GPS was a 3amp fast blow fuse, 250 V if I remember correctly, I'll have to double check. The GPS has been plugged into the factory plug for almost a year, so I know thats not the issue.

 

You may not have to take it apart if you know how to check the voltage at the aux plug. Stick one of the multimeter/voltmeter leads on the side of the aux plug and one at the very bottom where it has a nipple like shape. This should give you a voltage reading. If you can not get an reading like this, you may have to take apart the splice connecting the aux plug.