Tapping into trailer wiring
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Tapping into trailer wiring
I have a 2003 F-150 4.2L with the standard trailer towing electrical on the rear bumper. I have 2 questions. One, my camper shell has a factory installed 2 wire dome light I would like to put power to? Second question: Is it feasible to add an auxiliary fan to cool us off in the summer and mount it to the camper shell, if so, how would I best power it? Can I tap into the trailer wiring (I don't tow anything)? I appreciate any input from the forum.
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Joined: Apr 2011
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The problem with your trailer wiring is that there is not a dedicated (or on that is on alll the time) source of power. In order for your light or fan to work, you would have to leave your parking lights or brake lights on for them to work..
My suggestion is this: Go to radio shack, wal-mart, auto parts store or the like and get the following:
1. About 20 ft. of red automotive wire (12 or 10 gauge).
2. The same amount of black wire of the same size.
3. A 4 pin trailer type connector. (Should have 2 sides to it)
4. A package of 1/4" wire loom
5. Wire ties
6. A blade type fuse holder and a 20amp fuse.
7. Some solder and soldering iron/gun
8. Heat shrink tubing and electrical tape.
9. Ring connectors that will fit the wire you get and your battery terminals.
This of course is assuming that your light and fan have switches in them.
In the inside of the bed. There should be a hole in the front and rear stake pockets. Pick one of those (I would suggest the front) and route the wire down through there. Pull it along side your frame taking care not to get to close to the important things (exhaust, shocks etc.) up to the battery. Do this for both colors.
Tie off these wires at the battery, making sure you have enough of each color to hook to the appropriate post. Insert both of these into the wire loom and securely wrap a little tape around the loom every few feet.
Secure the wire loom along the frame every few feet. There are several extra holes here and there alongside the frame to do this.
Take the four pin connector, taking the side that has the 3 insulated post, Pick 2 of the insulated ones and after putting the heat shrink down over the red wire, solder the appropriate 2 wires to the red wire. Pull the heat shrink over the connection and then heat it to shrink. Repeat the process with the other 2 wires and the black wire.
Take 1 each of the wires you made positive and negative and repeat the solder/ heatshrink process with those wires, connecting them to either your fan or light. Repeat the process with the other two wires.
Now.. the business end. Take the black wire and securely connect one of the ring connectors to it. I would suggest tinning the wire with some solder before you crimp it. Then connect to your negative battery terminal.
Most of the fuse holders have a 6" or so pigtail of wire on both sides. Repeat the process above for the ring connector on one side, and then solder the other side to the red (positive) wire covering with the heat shrink.
Go back over all of your connections and the wire routing to make sure they are secure and you do not have the wire too close to anything that it shouldnt be. If everything is good, then install the fuse in the holder. Voil'a, you should be good to go now!
My suggestion is this: Go to radio shack, wal-mart, auto parts store or the like and get the following:
1. About 20 ft. of red automotive wire (12 or 10 gauge).
2. The same amount of black wire of the same size.
3. A 4 pin trailer type connector. (Should have 2 sides to it)
4. A package of 1/4" wire loom
5. Wire ties
6. A blade type fuse holder and a 20amp fuse.
7. Some solder and soldering iron/gun
8. Heat shrink tubing and electrical tape.
9. Ring connectors that will fit the wire you get and your battery terminals.
This of course is assuming that your light and fan have switches in them.
In the inside of the bed. There should be a hole in the front and rear stake pockets. Pick one of those (I would suggest the front) and route the wire down through there. Pull it along side your frame taking care not to get to close to the important things (exhaust, shocks etc.) up to the battery. Do this for both colors.
Tie off these wires at the battery, making sure you have enough of each color to hook to the appropriate post. Insert both of these into the wire loom and securely wrap a little tape around the loom every few feet.
Secure the wire loom along the frame every few feet. There are several extra holes here and there alongside the frame to do this.
Take the four pin connector, taking the side that has the 3 insulated post, Pick 2 of the insulated ones and after putting the heat shrink down over the red wire, solder the appropriate 2 wires to the red wire. Pull the heat shrink over the connection and then heat it to shrink. Repeat the process with the other 2 wires and the black wire.
Take 1 each of the wires you made positive and negative and repeat the solder/ heatshrink process with those wires, connecting them to either your fan or light. Repeat the process with the other two wires.
Now.. the business end. Take the black wire and securely connect one of the ring connectors to it. I would suggest tinning the wire with some solder before you crimp it. Then connect to your negative battery terminal.
Most of the fuse holders have a 6" or so pigtail of wire on both sides. Repeat the process above for the ring connector on one side, and then solder the other side to the red (positive) wire covering with the heat shrink.
Go back over all of your connections and the wire routing to make sure they are secure and you do not have the wire too close to anything that it shouldnt be. If everything is good, then install the fuse in the holder. Voil'a, you should be good to go now!
Today, 02:31 AM Teamramrod46, Thanks for your timely and comprehensive response. I will post how it turns out.
