Driver_Lost

That's because its a ground circuit that turns on the headlights. The test light worked as a jumper wire.

Its really smart to wire a high amp circuit like the headlights that way but it makes it a little tricky to figure out. I actually learned this through messing around with my headlights & fog lights. I rewired all of them real easy once I figured it out. Like I wired up my fog lights to come on independent of all other lights

And on my other B I also made it so both the high & low beams work together. Not recommended for a dual filament bulb but ok for independent bulbs like the FFX JDM type.


So it sounds like you found the problem and that's huge when it comes to electrical grief.

cough

It appears that the horn wire may be the culprit. I visually inspected as much of the wiring under the hood as I could and didn't find anything else that caught my eye. I went to the parts store and got female spade connectors and cleaned it all up and reconnected the horn. During the reconnect, I noticed that the wire was really tight and I was concerned that it would break again or something, so I removed one of the harness retaining clips to the steel under bumper bumper,(if you've removed your bumper, you should know what part I am writing about) and that loosened things up enough that the wire reached the horn and still had a little slack in it. I'm thinking 6 years of salt and grime may have corroded the wire off, maybe..I'll never know. But only time will tell if that indeed is the fix. We're expecting to get real cold, single digits, again real soon. I'll update either way. Thank you everyone who made suggestions and comments, you allowed me to think objectively and clearly, and directed me to look for things I hadn't thought of.