Brain Buster! I need a power source!!!!

Imprezive · Post by **Imprezive** » Fri May 19, 2006 5:30 am

Ok, so I tried to get my car smogged today, and I unplugged the CEL light so it didnt come on but they noticed it didnt come on at all. Dont ask why it comes on in the first place... So I am devising a way to make it so the CEL will come on when the ignition is turned to the "ON" position but will turn off when the car is started. I picked up a 12v relay and a 12v LED light at radio shack, and I'm ready to do this, except I've got a problem. I need a power source that will be on when the ignition id turned to "ON" but off when the car is running. I tried asking the guy at Radio Shack who has apparently done it before but he only said "you'll figure it out..." he was no help...

Anyway, I have a very, very basic knowledge of electrical stuff, and so far I cannot think of one thing that will turn off when the car is running but be on when its not running.

jnorion · Post by **jnorion** » Fri May 19, 2006 5:35 am

The easiest one is the switched power that runs to your stereo. But you can also find a wire in the harness coming from the ignition switch... if you test with a volt meter and find one that's live when it's on, then turn it off and see if the power goes away.

Imprezive · Post by **Imprezive** » Fri May 19, 2006 5:45 am

But the stereo is on when the car is running. I need power that is there when the car is on the "ON" position but the power needs to go off when the car is running....

jnorion · Post by **jnorion** » Fri May 19, 2006 5:54 am

Ah, I misunderstood. You'd probably have to tap directly into the ignition switch then, before it even gets to the main power wire.

Or you could wire the light into another warning light that doesn't come on normally, so it'll do the main check but nothing else.

Imprezive · Post by **Imprezive** » Fri May 19, 2006 6:18 am

I just thought of something, I have to input 2 power sources into my relay, so if I find something that comes on when I start the car but is off when the ignition is just on the "on" position I can T off the positive wire power source into the ground on my relay which will turn the relay off. Although I'm not sure if that is good for my ECU.

Vikash help me!!!

Edit: I just thought of a possible power source: RPM signal? What if I spliced into the Oil idiot light so that it powered both lights but then they both turn off when I star the car???

Brian Mau · Post by **Brian Mau** » Fri May 19, 2006 7:21 am

Imprezive wrote:I just thought of something, I have to input 2 power sources into my relay, so if I find something that comes on when I start the car but is off when the ignition is just on the "on" position I can T off the positive wire power source into the ground on my relay which will turn the relay off. Although I'm not sure if that is good for my ECU.

Vikash help me!!!

Edit: I just thought of a possible power source: RPM signal? What if I spliced into the Oil idiot light so that it powered both lights but then they both turn off when I star the car???

What about hooking it up to the "Charge" indicator on the dash? It's on before you crank and off after you start it.

scuzzy · Post by **scuzzy** » Fri May 19, 2006 12:59 pm

Brian Mau wrote:
Imprezive wrote:I just thought of something, I have to input 2 power sources into my relay, so if I find something that comes on when I start the car but is off when the ignition is just on the "on" position I can T off the positive wire power source into the ground on my relay which will turn the relay off. Although I'm not sure if that is good for my ECU.

Vikash help me!!!

Edit: I just thought of a possible power source: RPM signal? What if I spliced into the Oil idiot light so that it powered both lights but then they both turn off when I star the car???
What about hooking it up to the "Charge" indicator on the dash? It's on before you crank and off after you start it.

If you do that don't use the relay, just wire it in directly. both lights should be resistive enough to where they both get some juice when they're lit.

Imprezive · Post by **Imprezive** » Fri May 19, 2006 5:24 pm

The little battery light? Thats what I thought of this morning, I figured the charge indicator is the most useless so if something goes wrong it wont be as big a deal as if the oil light breaks, I'd rather know my oil pressure or level is low than if my battery is dead if you know what I mean.

Post by **Legacy777** » Fri May 19, 2006 5:51 pm

Your best bet is to just tie into one of the other lightbulb leads going to either the charge lamp or the oil lamp.

I will say this though.....you're going through a HELL of a lot of work just to try and circumvent this. What the hell is wrong with your car, and is causing the CEL to come on?

Imprezive · Post by **Imprezive** » Fri May 19, 2006 6:27 pm

Well I'm getting some funny CEL's, something w/ the purge control solenoid, and the MAF, and something about the cam angle sensor. The IAC is also F'ed up. I need to get them fixed, but I also need to get my car smogged by the end of this month. I'll have to pull the codes again to see exactly whats up. The MAF and the Cam CEL's have me concerned the most. But the car is running fine. It could have something to do with the EJ20G in place of the EJ22T

Figuring out and fixing the problems to get the CEL off will be harder than just doing what I am doing, plus more expensive.

I'll have the fix done this afternoon, I'm just mad that I wasted $10 on a relay that I dont even need

scuzzy · Post by **scuzzy** » Fri May 19, 2006 9:39 pm

Imprezive wrote:Well I'm getting some funny CEL's, something w/ the purge control solenoid, and the MAF, and something about the cam angle sensor. The IAC is also F'ed up. I need to get them fixed, but I also need to get my car smogged by the end of this month. I'll have to pull the codes again to see exactly whats up. The MAF and the Cam CEL's have me concerned the most. But the car is running fine. It could have something to do with the EJ20G in place of the EJ22T

Figuring out and fixing the problems to get the CEL off will be harder than just doing what I am doing, plus more expensive.

I'll have the fix done this afternoon, I'm just mad that I wasted $10 on a relay that I dont even need

I think you need to fix your car, not circumvent smog. Then again, where do I have room to talk? I'm driving around with little more than just headers.

OH well.

Imprezive · Post by **Imprezive** » Sat May 20, 2006 2:28 am

scuzzy, the whole point in me doing this is so I can get it smogged because I need to smog it buy the end of this month, the tags still say '05 on them.

Anyway, I cannot find the power for each individual light, I didnt find power on the left hand side plug that plugs into the gauge cluster, but it doesnt turn off when the car is running, I am thinking there is something built into the gauge cluster that shuts the light off somehow...I dont know...

jnorion · Post by **jnorion** » Sat May 20, 2006 3:13 am

Just pull the other warning light out from the back and run a wire to the CEL.

Imprezive · Post by **Imprezive** » Sat May 20, 2006 4:23 am

the lights plug into a printed circuit board, so you cant just run wires to them. but I figured it out;

If you unplug the connector on the left hand side of the gauge cluster, you can splice the + and - of the LED light into it.

Stinky · Post by **Stinky** » Tue May 23, 2006 12:07 am

I have thought of doing the same for mine to get thru smog.
I was going to use the accesory voltage to turn it on, then use the "start" wire to the ECU turn it off, plus the optional second delay, just for kicks. I was thinking of using a simple 555 timer circuit. Accesories would tigger the LED, then 'start" would reset it to turn it off after a delay. The 555 timer has been around since the '70s and is pretty well documented on the web(an available at Radio sHack for < $1).

...just a thought.

I haven't had time to work it out yet, but it seams possible. But I think you'll have to add some simple control electronics (like a 555 timer). I'm not aware of anything that you could just 'tap' into that would have the logic you need to control the relays.

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Brain Buster! I need a power source!!!!

Brain Buster! I need a power source!!!!