Hi,
Does anyone know what colour the ECU power wire is? I'm planning on kill switching it. This will stop the engine from starting right? Any risks involved with this?

Thanks, Dan.

 

Bump
Has anyone tried this? I can't even find which is the power wire in the Haynes manual. I havn't looked at the FSM yet, is it in there?

 

what year is it. Its white/black comming out of fem-02 in an s4 and im pretty sure its the same on 89. The ecu plug number is 3J on s4 and 1A on s5. What is your reason for putting a kill switch on the ecu. If its for security reasons just attach it to the starter not the ecu. Nothing good can come out of connecting and disconnecting power to the ecu. You also get a better chance of shorting the ecu out by doing this.

 

Hmm yeh it was for security reasons. I was going to put one kill switch on the starter motor, but then also another on the ecu for when i have to park it in really dodgy areas, otherwise i wouldn't use it. But i guess it's not worth the risk... Shame because the starter motor won't be that hard to trace for someone breaking in, just rip the wire going to the switch off and join the two and walla it's back together again. I mean i'll be getting an alarm too, but that's in a little while.
Alright well thanks for the advice mate, i'm not going to bother with it. Just to be certain, what colour is the starter motor wire?

 

Dude, here is what I did. I have two 88's. On the main fuse block under the hood by the battery compartment, there are two fuses marked (1) EGI (2) EGI inj .
On either of these cut the wire and attach male and female connectors that are shielded (no exposed metal) and install a toggle switch (I put mine in the glove box). the two wires coming from the toggle switch has one each of male and female connectors to match what is on the wire leading to whichever fuse. This has worked for me. I don't like to mess around the ECU any more than I have to. This was pretty easy. The hardest part is running the wires and installing the switch. I drilled a hole in the lower left side where the back of the toggle assembly will clear all the underdash clutter. You will need to pull the glove box out to see.
Good luck. I used a 50 amp switch since I didn't know the current on that curcuit. This has been working for four years.
Good luck again.

 

About the above posts:

Pin 3J (White/Blue) being disabled Will Not disable the running of the engine. It's powered by the BTN fuse (60A). Go pull the BTN fuse OR depin pin 3J and you'll find the car starts up and runs just fine.

Pin 3I (Black/White) being disabled will kill the car dead in it's tracks. It's being fed from the 30 amp EGI COMP fuse. There's not a dimes bit of difference b/t disabling it at the ECU or at the engine fuse box. It's the same circuit. Goes from the EGI COMP to the Main Relay to pin 3I on the ECU.

On a 87 car there is a INTERLOCK switch on the clutch pedal. It has a BG and a BR colored wires. The BG leaves there and goes to a STARTER CUT RELAY if you had a factory alarm system. If you don't have one, then it goes to the same location under the Trail coils assy, but instead of a relay there is a jumper wire in a plug. The BG is jumpered to a BW wire that goes directly to the starter motor.

http://www.teamfc3s.org/forum/showth...threadid=29908

 

I did what Harley did and it works fine. I inserted a switch into the circuit right under the fuse block, ran a two line zip cord through the firewall and installed a rocker switch in the indent just above the hood release ( I had the dash out).
Anyway, you can't see it and could only turn the car on if you knew it was there.
I have hi-res pix if you're interested.

- k -

 

Quite happy for you. Pictures not needed. I was just clearing up the mention of 3J in one of the upper threads. I totally agree if you disable the EGI COMP or the EGI INJ fuse the car will die in a heartbeat. Disabling 3J will not do the above. Just nitpicking.