Gene,
Here is what I would do. First things first - get yourself an inexpensive multimeter, like this one:
from Radio Shack for a couple of sawbucks.
Then, once you get your new toy home (and you have batteries for it), take your wedding ring off, if you wear one (if you have objections to removing your ring, then wrap it with masking tape). You may ask why? Glad you asked - while we're just dealing with 12 volts, the amperage (the amount of current) drawn can be VERY high, especially when you have a direct short. With household current (110v AC), if you touch a "hot" wire, you'll get a tingling sensation (or more if you have not been in the habit of touching them all of your life). This tingling sensation will cause you to drop the wire. With 12 volts, you don't get this sensation, but you can get arcing which is just like welding - you don't want your wedding ring or any other jewelry to act as the "short" of your welder and remove a finger!
And, while we're talking about fingers, when you touch the wire ends to the black and red probes, respectively, don't pinch them with your finger and thumb - the moisture in your fingers and the saline solution in your body *can* produce a "short" such that the meter will recognize it.
Okay, now that disclaimers have been made, the next step is to remove the fuse for that particular circuit. We don't want power going through these two wires to your lamp. At least not while we are looking for the short.
Set your new multimeter to "Ohms" or "Resistance". Touch both the red and black leads from the multimeter together and notice what the readout shows and if the meter "beeps". Now that you know what to look and listen for when you find a short, remove the lamp from the wall and then remove the wire nuts from the main wiring where it connects to the lamp wiring (take note of what wire goes where). Use the black and red leads from the multimeter and touch the black lead to one of the wires coming from the 5er and the red lead to the other wire coming from the 5er. Do you get a "beep" or a reading indicating a short? In all likelihood, you probably won't as I suspect the problem is in the lamp - just a hunch.
Okay, with bulbs in the lamp, connect the black and red leads to the lamp wires and rotate the switch. If you get a "beep", then no "beep", then a "beep", your lamp is okay. If you get a continuous open short reading, then your lamp is at fault. To verify, remove the bulbs and test again. The bulbs actually help to make a short when the switch is in the "on" position.
If it's the lamp, you could try looking at it and seeing if there is something obviously wrong. Or, get a new lamp; or, take it to an electrician.
If you did get a short reading with the 5er wires, it's probably time to take it to a dealer or have a repairman come out, based on your skill level. You could continue to track the wire pair back thru each junction to the panel, but this could be a big job.
Hope this helps.