yeah, I think I'm headed that way. I emailed Shiv and Chiptorque. I really wanted to figure this out myself, but I may need to punt.

 

post their replies online, i'd like to see what they suggest.

 

Wasn't sure why I was so hesitant to take it to an electrical guy. Thought about it a little. After all, if they charge even $100/hour it'll be under $100. Here's the problem, though. What if they're wrong and the circuit they design screws up the Xede? I want to know the theory behind anything that is added to the car (that and I'm probably a bit OCD). I'm gonna keep on trying to get some info from either Shiv or Chiptorque. Perhaps a daily email to both will eventually work.

I got on a Yahoo group sponsored by an automotive electrician offering to solve problems. We seem to have had a miscommunication. If you don't mind, take a look at the exchange and tell me how I can explain this better.

Autoelectric Group

 

Reading your post and his response gives me a thought. He said "You will not be able to do it using the voltage from the ecu
the 5 volts is a reference signal. It is therefore a maximum. most of the time it is below one volt."

I understand what he's saying. You may have read 5v from the xede, but he's saying that isn't constant. SO, you WILL have to wire in external power to light your lamp.

Now it's all a matter of drawing out the diagram for it. If you'd like, i'll give it a shot and maybe load something up within the next week for you.

If you DO hear back from shiv or chiptorque before i have a chance to get back to this thread, PLEASE PLEASE post the info. I'd like to hear what they have to say.

 

Ok. I've done some more research and have realized that this isn't going to work the way I want. First, though, from a purely theoretical standpoint:

You said that you understand what he's saying. I may have read 5v from the xede, but he's saying that isn't constant. How would he know that? I'll test it to see, but I even if it's true I don't think I gave him enough info to draw that conclusion. The question in my mind is whether the voltage drops when you bring it to ground. That may be what he means, but I can't tell from what he wrote and don't know how to verify that theory.

More to the point, however, is the fact that (from my research) I now understand that an LED either creates light or flows current. If that is correct, this circuit:

Xede-->switch-->resistor-->LED-->fuse(?)-->ground

cannot work, since the LED will flow current only when placed in the direction in which it does not create light. Instead, I would have to put an incandenscent light in series with the Xede. This still doesn't explain why the LEDs did flow current one way (enabling the map switch function in the Xede) but didn't create light when reversed. In fact, it begs the question, since if the master electrician is correct, the voltage drop would never occur in the LED-for-light position (because the circuit is never complete, being blocked by an LED).

So, now I have to decide between an incandescent light in series or an LED wired in with a separate power source, but controlled by the same switch (a single throw/double pole switch). The incandescent light would have the advantage of being activated by the current flowing from the Xede (assuming this would work), but would not be as reliable as an LED. On the other hand, finding an STDP switch for a WRX might be a PITA. I'll do some surfing. . . .

Thanks for the offer to diagram it. I'd love to have your input. I'll be working on it from this end in the meantime.

If I DO hear back from shiv or chiptorque before hell freezes over, I will be sure to let you know. You'll probably read about it in the newspaper: Man Goes into Shock After Receiving Customer Service Response.

 

On the other hand, could you split the ground side of the switch, running one to ground and the other to the LED? Sorta:

(ignore this space) ------->(resistor?)------>LED------>gnd
(ignore this space) /
Xede----->Switch<
(ignore this space) \
(ignore this space) -------gnd

It would probably have to be more complex to keep the current from just running to the ground.

Still hopeful . . .

 

Here's what I did.

1. Get a automotive 12v relay. I got mine here:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3058230049

Here's a basic explanation of a relay:
http://www.teamrocs.com/technical/pa...lay_basics.htm

2. Wire the relay according to the attached diagram.
(sorry, I don't remember which wire corresponds to what pin.
I think white is 85, black is 86, red is 30, blue is 87a and yellow is
87).

This should ground the Xede when you turn on the switch, as
well as light up a LED. If you don't know what resistor value to
use, you can just get a pre-assembled Resistor + LED unit.

HTH,
-PGM

EDIT: For the diagram, go to http://briefcase.yahoo.com/yocheerio
and look at xede_gnd.gif

 

Just what i thought. You confirmed what i was thinking.

This:sounds a lot like this said earlier:

 

PGM:

I can't believe it!!! An ANSWER!!! You have no idea how much I appreciate this. I had just downloaded and printed about 50 pages of a web page published by a high school electronics club in order to figure out what each type of electrical component does and how it works. They had some example circuits that were tantalizingly close, but none were on the money.

Jgrahn555:

Thanks for sticking this out with me. If I had known anything about electronics design, I would have been able to take your suggestion and make it work.

 

No prob! Good luck, lets get some photo's when it's done, eh!?

 

Juliano,
No problem. I spent a lot of time on this couple of months ago
as well. If you want to see the diagram, let me know and I can
email it to you.
-PGM

 

You can also walk into any Radio Shack and buy an SPST 12v 30-amp automotive relay for $5.99, part number 275-226. I've used these for wiring things like air horns and MSD ignition boxes in the past.

EDIT for part number.

--
0==WW==0
"…axles of evil…" - george w. bush

 

yes, but now the task is to find a lamp with a relap built in (if such exists). I think these would be useful.