Fox T-Bird/Cougar Forums  

The brown wire is for the parkinglamp/running lamp circuit. Yes one wire already does handle the entire set of three bulbs plus license plate and side marker lamps on each side as it travels the entire length of the floorboard into the trunk area with one brown wire. The brown wires from each bulb socket are all junctioned at some point in the rear body panel harness all soldered together and taped up.

Ah - I haven't seen that spot. Any idea where it is? Is it the same gauge wire there, or is the feed larger? I was wanting to tap into the existing harness in the middle of the rear, just to the drivers side of the latch (with exception of the green/drivers side turn/brake wire being a couple bulbs away).

If the feed wire is larger, I'll just run a jumper over there from my current splice location but it appears to be further up the quarter panel?

The brown wire should be seeing about 6A of current going through it with the lights running, using standard incandescent bulbs.

That's strange but not surprising. What I hate is how Ford has smaller wires on a fused circuit that is designed for a larger wire that is also on the circuit.  My radio/clock memory wire burned up when the fuse was sized larger than that wire can handle. The thing's just sitting in there now, chopped off since there was nothing left but bare copper. I'd like to replace it someday but that's a huge ordeal to do, especially with a thicker wire. Right now I use a dedicated run with its own 5A fuse...

Anyways, got the things wired up and all's well for the moment. I may just replace them with some 3W LED's just to try them out (first one as a test of a product). The lower power draw, instant on, more consistent light output, and the ability to easily get some that are around 30% brighter than the stock lights makes is a no-brainer if the bulbs can be found somewhere for cheap (NOT retail pricing).

At some point I would love to do all exterior LED's...

So yeah - umm...how does the system sentry detect that a lamp is out? With all rear lights wired up to a single wire, when I turn them on, the lamp out light comes on. Also with the lights off, during braking it's off but with my sequential turn signals on, I get a very short flicker from the system sentry each flash. This I'm not too concerned about though as it would make more sense than the illumination bulb out thing.

So why is it saying I have a lamp out with the rear taillights on when all 8 rear bulbs are fully functional and wired to the same brown/black wires? Yes this belongs in the electrical section :p

What would it measure though? Just the increased resistance from the one wire being used? That'd cause the system to turn the bulb off I would think. The only difference is the two inner bulbs are now dual filament but I doubt that would cause the illumination to throw a bulb out indicator. Perhaps it measures the brake/signal circuit instead, even if the brake/signal aren't supposed to be lit with only the illumination on?