Thanks for all the help and feedback guys, I'm going to have downtime later this week (thurs/fri/sat) to do more testing - I'll report back what I find out.
Quote:
Originally Posted by StickMon
The current limiting for the LEDs is built into the light, so you can run it directly off 12V.
The transistor acts like a switch. Where it says "30" is the voltage source.
The transistor will be open when the light's off, closed when it's on.
The little rectangle above it is a small value resistor that's used to measure the current going to the bulb for the sake of the bulb out warning.
I think Samuel established in post #8 that the light is good, just not getting power.
Next thing would be to get at pin 16 on the back of the Light Switch Cluster, where the black/yellow wire comes from, and see if there's voltage there (with the brakes on, of course.)
If not, it doesn't look good for the Light Switch Cluster.
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^
I'm going to walk back through everything I have tested so far to rule out everything that I can. After that, I guess I'll have to start looking at the X12 connector (*cue ominous music*).
Quote:
Originally Posted by GuidoK
If I read the wds diagram correctly you might not be able hook up the 3rd brake light directly to a 12v power source (battery or so). There is a transistor in between (in the light switch cluster) that might be there just to turn on the light, but it might just as well be there to limit the current (the diagram is not conclusive in that). You can try hooking it up in series with a 5W resistor, 120 ohm or so (that's a guess, the leds are paired in clusters, so the right amount of current depends but I think this is a safe setting: 120 ohm limits the current to 100mA). If you dont see them dimly lit, theyre broke or get not enough current (use them without the resistor).
If you have a current limiting power supply you can use that (but you probably haven't or you wouldn't have asked this question)
But I expect that you have a broken wiring loom somewhere. At the trunk hinge is the most likely area provided your car hasn't been tempered with by an incompetent mechanic in the past.
If you want to measure continuity on the wiring loom, the light switch cluster (A3a) is located here:
There is a black&yellow wire going from that light switch cluster all the way to the 3rd brake light. And from the 3rd brake light there is also a brown wire going to earth. Thats the easy one to measure  |
^I managed to get dim light from the LED strip, but my testing setup was extremely crude. I'll look at these again with some more precise measurement when I check back over everything.
- *off topic* GuidoK, your VANOS guide saved my @$$ last year - so I'll take suggestion you've got
