Re: Tailer light help
Sounds like youve grounded out either your yellow or green wire somewhere. Below I posted this "mini-howto" I put up on another forum. I know your using a wired ground instead of a frame ground. Same things apply, you just have a lot more wire to deal with.
http://www.accessconnect.com/trailer_wiring_diagram.htm
^ this is a good wiring diagram of what your probably doing.
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beg/buy/steal/borrow a multi-meter. Usually cheap and worth every penny.
First. Find a good ground. Follow your white wire down to where it connects to the trailer's frame clip the negative (black) lead to the bolt.
Next open the taillight housing and remove the bulb. Inside the bulbs base you will see a metal seath, and two metal pins or plates on the bottom.
Switch your multimeter to resistance (ohms, or the latin? omega symbol) the display should indicate 1, or open circuit which means there is no path for electricity to flow through.
Touch the positive lead (red) to the outside seath of the connector. It should read zero, or similar because there is a complete cuircuit for electricity to flow through. If it reads 1, the connection has no contact to ground. Inspect the white wire.
Touch the positive lead to one of the metal pins at the bottom of the connector. If there is any other reading other then 1, the wire or connector has been grounded out, causing the fuse to blow. Test the other connector. Again if 1 is displayed, all is well.
Repeat this process on the other side. By what you have discribed I suspect the fault is either on the green or yellow wires. These wires also handle the brakelight function as well. Depending on you vehicles wiring, you might also blow the brake light fuse if you step on the brakes.
Method 2
Insert the negative lead into the trailer wiring connectors ground. The white wire runs into this. Follow the wire where it meets and you should have a resistance value of zero or near by it.
Insert the negative lead into the turn signal connector. The green wire runs into this. Then go to the passengers tailight housing and probe the connector. You should get a reading of 0, or close.. This wire is good to go.
Repeat for the rest of the wires. Now. lets say the green wire comes back with a 1 value. This means somewhere the wire is broken! You could backprobe the connector to the tailight, but I would test the tailight itself, if it passes, replace the wire, and vice/versa.
Now you have also said youve run seperate grounds to each tailight housing, which is fine. Its just that much more wire to trouble shoot.
Personally I ran my ground to the frame, but thats just my way.
If youve done all this and still have no luck, start looking at your F150 for answers..
I hope this helps!
