duffymahoney

Steve, is this your idea? I try to not cut any stock wires or drill any holes. I did my entire ITB install without a single new hole in my low mileage series 1.

Well I want alternator and turn signals! Tach is wired for my coil on plug. It works perfectly. I think my next step is to ohm check all the other ignition wiring that toned out and post the data.

My basic plan for the pink wire. Using the B/W spot for my pink wire. Then use the haltech fuses to give 12v to my iac.

It has an expandable fuse and relay box. I have 4 open fuse spots. 2 open relay spots.

Yeah, I have already de pinned the B/W wire from behind the ignition switch, I believe I have a few extra connectors for the stock pins. So install it there, inline, but fuse protect it. That makes perfect sense to me.

Well interesting, I will have to look which wire this is, ballast or off the back of the tach, I assume an ohm reading will be best for that. I see the ballast circuit goes off to other branches, and would be a not as nice spot for me to tap 12v from. I will ohm check the rest of the ignition wires, but they also seem to go off and branch. I will put a fuse inline no matter what I do. What circuit would you tap for the keyed 12v to my haltech? Behind my dash I found two, one was defrost(unplugged since I got the car) and the other is a ?. I was using the defrost, it's just a relay switched 12v, so very thin wire, so I assume low amp draw. I do own a brewery and a wakesurf boat:) Come on up.

Well I thought I knew exactly what it was. 12v positive for the coil. Which I wasn’t using. Since I have coil on plug. Getting fed directly from my ecu. I thought it was a simple way to wire my iac. But that turned out to be less. I regret it for sure. It would have been easier by a lot, to just run a circuit off my haltech. Whoops

First test. This is one of the black and white wires for the ballast/ coil. Grounding to my shock tower. Klein MM200 multimeter. Both the behind the tach is unplugged and so is my keyed ignition

I will start doing more testing later. I will get details on my meter and what I am seeing. I feel like this all started when my son decided to leave my car in the on position overnight. But maybe not. The short is strong enough now, to drop voltage down enough to cause the haltechs relays to drop connection and cause the ecu to turn off, while cranking. It's how I started down this fun rabbit hole. I can also smell, burnt wiring when the key goes to on. Sadly it's not as simple as just finding another keyed 12v for the haltech, I will need to fix this properly.

I was putting a positive lead into the ignition plug and getting a tone on each of those wires.

Well F. B/W, R/W, B/R and B/Y all tone your ground on my ignition

The ignition B/W and the W/R seem to be fused. Or am I reading that wrong?

I have dealer installed AC. So it's behind that beast! Darn

I am worried about both the B/W and the W/R wiring. I can't seem to find a way to disconnect the engine harness from the dash, the schematic seems to show a plug, but I cannot find it. Googling now.

Well I’m guessing this is the BW wire I was using. Which is melted at the plug.

You lost me on that. But I found my first melted wire. Off the ignition. The black and white, looks to be the ACC circuit. I can smell the burnt wire as well

I wish there was a way to find where in the harness the short is. Like some sort of heat sensing device.

I’m using all the stock wires on my haltech. But I have 2 open relay/ fuse spots. So it would work fine, I could run the 12v positive. Honestly I was just trying to be lazy.

True. The stock coil + must have no fuse? I honestly don’t know if the wire in using is the coil + or the ignition keyed +. I will have to look for that.

I have coil on plug. I have the coils positive looping through the back of my stock tach (works perfectly). the iac uses less then 1 amp. So the wiring is plenty big. It just needs a 12v positive. Then the ecu pulses a ground to it. I can keep in wrapping the tape till I hopefully find the short. Then replace that wiring. So far all the wire looks great. I will also look at behind the dash. Maybe the short is on that side.

So the green and white should be a ground? Then the other black and white should be another keyed 12v? Do either share any wire? I honestly only need a single 12v for my ITB iac. That’s isn’t shorted. So I could abandon the shorted one.

I have never taken the dash out. I will have to try and find the engine wiring harnesses connector.

Both the other green and white and other black and white are not shorted.

Steve you rock! The coil positive has a full short in it. Haven’t found it yet.

I’m trying to track down a short in my 12v positive from my tach to my coil. I seem to have two black and white wires and a green a white in my coil bundle. Any ideas? The 2nd b/w and green/white doesn’t show up on any wiring diagrams. I have a 1/71 build.