singleshot

I'm in search of a wire(s)

I'm looking for the location of the wires that run our dome light in or near our dash area. Specifically, I'm looking for the exact wire(s) that run our dome light during the remote locking/unlocking of our vehicles.

I'm not exactly sure how the that part of our system works yet, but it's on some sort of timer with a fader circuit and that would be the exact circuit that I need to tap into. Again, if you have a diagram and can find this circuit in the dash area, I would be deeply indebt to you...

Any help on color and location would be much appreciated..


Thanks
Singleshot

couped

The dome light runs off of a switched ground circuit. The positive wire is always hot. When the switch is moved to the "On" position, a constant ground is applied to the light. When the switch is moved to the "Door" position, the ground is controlled by the door lock control relay. Note that the door lock control relay is sensitive to incorrect wiring(reverse polarity, short circuits, and high loads) and can be damaged easily. It is exspensive to replace too. Do not attempt to tap into it unless you are confident that you know what you are doing.

The dimming function of the light is not caused by a voltage drop. It is created by pulsing the negative signal slower and slower until it is cut out completely. With a traditional incandesant bulb, the filliment cools relatively slowly and it creates the fade effect. If you replace the bulb with something solid state like an LED, you can actually watch it flicker as it turns off. I'm not sure what your plan is, but keep this in mind.

If you download the wiring diagram that is stickied at the top of this forum, you can find the info you seek. The actual circuit is drawn out on page 64 that is located in "064-065 interior light.pdf". The first part of the file name is the page numbers it covers. You'll see Red wire with Yellow stripe marked "R-Y" going from the door lock control relay(D4) to the interior light(I14). That is the dimming(pulsing) ground. It passes through a connector called (IB2).

The exact location of (D4) can be found on page 30 of the wiring manual, and (IB2) can be found on page 35. You should be able to tap that red & yellow wire anywhere between those two points inside the dash.

Alternatively, you can run a set of parallel wires from the domelight housing itself. If you remove the lense, you will see small round metal pads on each side of the bulb that are fairly convenient to solder another set of wires to.

I wouldn't recommend adding anything other than LEDs to that circuit. It is not designed for any substantial current draw at all. Too large of a load will burn out the door lock control relay. You can't even use another relay to drive a larger load as the relay will buzz as the ground is pulsed. If you are connecting anything other than LEDs, I would recommend tapping a relay into the door trigger wires. You won't get the dimming effect, but it will be safer.

If you serach around, Tomas has posted some more in depth info on the dome light circuit. It is definitely worth a read before jumping in. Hope that helps

singleshot

that's perfect... Thanks tons for all that info. Believe me, it will save a lot of time poking and testing vs. getting the job done...


Thanks again
singleshot