VTEC light having issues :S

Kinked210 · #1 01-21-2004, 09:21 PM

Okay, I just got done with that VTEC light thing..I'm pretty sure I did everything right...here's my problem:

I halfturn the key and it lights up (very very brightly by the way) along with the battery light etc...

Then when I completely start the car, it doesn't turn off, it just gets really really dim..and hard to see unless its night time.

When my VTEC kicks in (5900-6000 RPMS...is that late?) the light just turns off.

So instead of it being off and turning on at VTEC, it is on and turns off when it kicks in. Whats the deelie oh yo?

GScivic7 · #2 01-21-2004, 09:55 PM

might be a bad ground, and did you use the 330 ohm resistor? supposed to wire that inline with the positive end of the wire going to the ecu.

Kinked210 · #3 01-21-2004, 10:10 PM

o snap...i wired the resistor to the NEGATIVE wire that leads to the ground!

that the problem?

Kinked210 · #4 01-21-2004, 10:11 PM

on the instructions from hazone.com it says to solder it to the negative wire...

GScivic7 · #5 01-21-2004, 11:27 PM

there's no reason you need to solder it to the negative, the negative is just a ground, it doesn't need anything to regulate the voltage, impedence or whatever that is going to it. Wire it to the positive wire. It needs it on the positive wire because the LED can't handle the voltage going to it. That's what the resistor is for.

Kinked210 · #6 01-22-2004, 12:13 AM

ooooh ok. well the instructions are wrong then lol. both instructions i read said to solder it to the negative wire...

GScivic7 · #7 01-22-2004, 12:19 AM

that just doesn't make any sense to me. The ground doesn't need to be regulated like that. Can you link those instructions? I'd like to read them and make sure I'm not talking out my ass. Because that really doesn't make any sense to me

GScivic7 · #8 01-22-2004, 12:21 AM

i foudn the instructions from hazone.net it still doesn't make any sense to me, i'm going to do a lil googling and see what i come up with.

GScivic7 · #9 01-22-2004, 12:32 AM

okay, so far every instruction I read didn't say anything about that resistor. Try wiring it up without it first. Double check your install too and make sure you tapped the right wire and everything.

Kinked210 · #10 01-22-2004, 12:51 PM

I did it without the resistor but my uncle and one of my friends strongly suggested I leave it on so it regulates the flow and stuff.

Maybe I hooked it up to the wrong wire because there's two green/yellow wires that go into my ECU.

I just picked one randomly and tried it. Should I try the other one now?

chimchim · #11 01-22-2004, 01:03 PM

Quote:

Originally Posted by GScivic7

there's no reason you need to solder it to the negative, the negative is just a ground, it doesn't need anything to regulate the voltage, impedence or whatever that is going to it. Wire it to the positive wire. It needs it on the positive wire because the LED can't handle the voltage going to it. That's what the resistor is for.

Huh? What do you mean by "regulate the voltage"?

Anyways, since the LED is in series with the resistor, it really doesn't matter what order they are put in:

VTECwire(12v) to +LED- to resistor to ground

or

VTECwire(12v) to resistor to +LED- to ground

both will work the same. Just make sure you hooked up the LED correctly. It is polarized, so you must hook the proper lead up. The round LED usually has a flat side to the head which is lined up with one of the leads (one of the metal wires sticking out of it). This indicates GROUND. The resistor is not polarized so it doesn't matter which end you use. To be picky, use a black wire (or wire with a line on it) for ground, and a red wire to indicate power (consistancy just helps later on in life).

Soldering only makes the connection more permanent. Bolting the wire to ground does exactly the same thing.

As far as the original problem, it sounds like the set up is not grounded properly. Or the LED is hooked up backwards and somehow the circuit is reversed biased which turns on the backwards LED.

Let us know what happens.

Kinked210 · #12 01-22-2004, 01:10 PM

So should I switch the positive and negative wires around?

Or should I try the other green/yellow wire in my ECU?

GScivic7 · #13 01-22-2004, 01:49 PM

to find the positive side of the LED, look for line in the metal inside the LED. The line is closest to the positive side of the LED.

And the resistor is used to regulate the current that is going to the LED so it doesn't burn out right? so why is it wired in with the ground lead, I just dont understand that part.

chimchim · #14 01-22-2004, 02:01 PM

More thought:
I halfturn the key and it lights up (very very brightly by the way) along with the battery light etc...

If it's VERY VERY bright, like brighter than you normally see an LED light up, you are probably over driving current through it somehow. This means that there isn't enough series resistance with the LED. This can be due to either: the resistor is too small and so too much current is flowing for the LED rating (where did you get the LED? Most RadioShack LED's are rated at 20-30 mA which for a 12v source means you want about ~300-600 ohm resistors). Or, you've hooked up the LED and resistor in parallel (or shorted the LED) which is a very bad thing. Check your connection.

Then when I completely start the car, it doesn't turn off, it just gets really really dim..and hard to see unless its night time.

This sounds like one end is floating (not hooked up or bad connection) or it's connected to a point of similar voltage.

When my VTEC kicks in (5900-6000 RPMS...is that late?) the light just turns off.

Means that both ends of the LED are exactly the same voltage. If Hazone is correct (which I assume it is), then when VTEC is on, that wire goes to 12v. Sounds like your other end might somehow be connected to power.

Just redo like Hazone describes:

VTECwire--------(+LED-)--(330ohm)--------chassis(which is ground)

So instead of it being off and turning on at VTEC, it is on and turns off when it kicks in. Whats the deelie oh yo?[/quote]

chimchim · #15 01-22-2004, 02:12 PM

Quote:

Originally Posted by GScivic7

to find the positive side of the LED, look for line in the metal inside the LED. The line is closest to the positive side of the LED.

And the resistor is used to regulate the current that is going to the LED so it doesn't burn out right? so why is it wired in with the ground lead, I just dont understand that part.

Let's see. Ok, circuit lesson time folks... let's see what I can do.

Voltage can be thought of as water. Let's say 12v means you have a water source elevated 12 feet into the air. The water wants to fall to the ground, but we're only gonna let it out of the source tank with a "circuit" or pipes that we decide. Following Hazone, we're gonna make our piping consist of an LED connected to the tank, and then a 330 ohm pipe from the LED to the ground.

LED's cause about a 0.7v voltage drop by nature (out of the scope of this post to describe why it's fixed that way). That means that there's about 11.3v between the resistor and ground. Using the electrical equation V=I*R, that means that about 30mA of current is flowing through the resistor. Now since all the water flowing through the resistor is also flowing through the LED, then we know that about 30mA of current is running through the LED. This is how the resistor regulates the current.

Now let's change our pipe setup. Put the 330ohm resistor pipe from the tank to the LED, then the LED to ground. .7v across the LED means that the resistor is experiencing 12v to .7v... which is still a difference of 11.3v. This means that the same amount of current is still flowing through the resistor, which dictates how much flows through the LED.

This is a real rough explaination but I hope it makes sense and helps.

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