Hard Wire Help

denoxia · 05-27-2005, 11:07 PM

I want to hard wire my GPS, radar detector, and CB. I have no idea how to go about this. I am sure I can handle it once I get into it, but I need some help on this one. Could someone let me know what I need to buy, like wire gauge, fuse, and so on? How do I go about this, do I cut in to another power wire? Which one? I have never delt with any automotive electronics and I do not want to burn up my wonderful Titans electrical system. Please help me out on this, pictures if possible would be great.

This is just my first electrical project, figured I would start out with these things first so I can learn. Later I am going to have to wire up my LED emergency warning lights and siren, much more indepth I am sure.

Just a firefighter

that needs some help.

Thanks

bestatchess · 05-28-2005, 07:33 AM

Here is an informative web site: http://www.the12volt.com/

You can add a circuit to the fuse box with the mini extender described in this thread:

Accessory fuse

The general rule when adding power wires is that you want to fuse the power wire as close to the power source as possible.

Other than the fuse box, a couple of potential power sources are:

1. dash lighter sockets: These are independently fused at 15 amps each. The driver's side socket is on all the time. The passenger side socket goes on and off with the ignition. If you pull the radio bezel off, you can tap the power wire for the passenger side socket from behind. In doing this, you should use an appropriately sized in-line fuse & holder. Keep in mind that the combined amperage of whatever you have plugged into the lighter socket plus whatever accessory you have tapped into the circuit cannot exceed 15 amps. (Depending on your vehicle, you may have another lighter socket in the center console that you could tap.)

2. There is an accessory power terminal on the battery, near the positive battery terminal. A power wire can run from that through the firewall. A couple of places to get through the firewall are: (a) the 1/2 plug on the driver's side firewall located behind the brake booster that you can see from under the hood and (b) a wire can be fished through the hood latch release cable grommet using a coat hanger. Anything you connect to the battery should be fused at the battery using an appropriate sized fuse. If you connect something directly to the battery, it will not go on and off with the ignition, so if you forget and leave something on, it will drain your battery.

A word about fuses: The fuse protects the wire and the device. The fuse needs to be located as close to the power source as possible. Suppose you run a wire to the battery and put an in-line fuse in the cab of the truck at the end of the wire remote from the battery. If there is a short (e.g. the wire rubs on metal and rubs the insulation off) in the wire between the battery and the fuse, the fuse will not blow. Rather, current will continue to flow through the wire until it burns through. Depending on the thickness of the wire and the location of the short, the truck may catch fire.

A word about wire gauge: You need to select a wire of an appropriate gauge depending on the current (amperage) to be carred by the wire. Here is a good web site: http://www.powerstream.com/Wire_Size.htm

A word about relays: If you want to wire a relatively heavy draw accessory, such as driving lights, you can use a relay, as described here:

http://www.the12volt.com/relays/relays.asp

juma · 05-28-2005, 11:16 AM

i would add that wire is important too. auto electric wire is a special hi -temp thin coating, not the same as the bell wire you buy at radio shack. anytime you run wire under the hood you want the txs or better wire with the crosslinked coating. because of what you are doing and the number of things you want to run, I'd bring a big 10 guage wire into the cab and set up a aux fuse block with several fused circuits build into it. that way you stay out of the titan mystery wiring and are sure of what kind of load you can put on the aux circuit. It is ok to use the titan wiring to trigger relays.

juma

denoxia · 05-28-2005, 04:58 PM

Thank you bestatchess and juma I am trying to get as much info as possible before I start this project. You guys have given me some great pointers and links.

homer · 05-29-2005, 10:50 AM

Hey guys, I plan on hardwiring an electronic compass into my Jeep. I bought one of the fuse adapters. When I popped open the cigarette adapter I found one wire (red) going to the spring clips on the sides of the adapter. Is this the ground? There is a white wire going to the springy thing in the center of the adapter which I assume is hot. Does this make sense or have I got it backwards? Before I solder new wires to these leads I figured I'd check with the experts. Thanks.

juma · 05-29-2005, 11:54 AM

Quote:

Originally Posted by homer

Hey guys, I plan on hardwiring an electronic compass into my Jeep. I bought one of the fuse adapters. When I popped open the cigarette adapter I found one wire (red) going to the spring clips on the sides of the adapter. Is this the ground? There is a white wire going to the springy thing in the center of the adapter which I assume is hot. Does this make sense or have I got it backwards? Before I solder new wires to these leads I figured I'd check with the experts. Thanks.

red wire by the usual convention is always a hot wire or a hot wire when the ignition is on. do you have a multimeter? its a good thing to have to check such things. all you do is push a pin through the insulation of the questioned hot wire and touch the pin with the red lead from the multimeter and ground the black lead. the multimeter should show 12. something volts if its hot. if you get nothing, it may be the ground. check the white next. a ground wire can be various colors but usually black is the most frequent used, white and grey are also used.

juma

homer · 05-30-2005, 04:43 PM

Quote:

Originally Posted by juma

red wire by the usual convention is always a hot wire or a hot wire when the ignition is on. do you have a multimeter? its a good thing to have to check such things. all you do is push a pin through the insulation of the questioned hot wire and touch the pin with the red lead from the multimeter and ground the black lead. the multimeter should show 12. something volts if its hot. if you get nothing, it may be the ground. check the white next. a ground wire can be various colors but usually black is the most frequent used, white and grey are also used.

juma

Thanks juma. I finally decided to just add a power socket behind my glove box, I put the adapter back together and I'll just plug it in there, out of sight.

Blizzard · 05-31-2005, 01:08 PM

If you hardwire your radar detector, you need to drive around VA on any trips you take or if you get caught, expect to be fined (I think it is $40 bucks plus processing fees or court costs). Even if the detector is turned off (but EASILY powered up) you are still in violation. They may let some things slide, but they are pretty fascist about the radar detectors on out of state vehicles.